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Tuesday, January 23, 2024

Antipodes

From Wikipedia, the free encyclopedia
https://en.wikipedia.org/wiki/Antipodes

This map shows the antipode of each point on Earth's surface—the points where the blue and yellow overlap are land antipodes; most land has its antipodes in the ocean. This map uses the Lambert azimuthal equal-area projection. The yellow areas are the reflections through Earth's center of land masses of the opposite Western Hemisphere.
 
The same map, from the perspective of the Western Hemisphere. Here the blue areas are the reflections of the Eastern Hemisphere.

In geography, the antipode (/ˈæntɪˌpoʊd, ænˈtɪpədi/) of any spot on Earth is the point on Earth's surface diametrically opposite to it. A pair of points antipodal (/ænˈtɪpədəl/) to each other are situated such that a straight line connecting the two would pass through Earth's center. Antipodal points are as far away from each other as possible. The North and South Poles are antipodes of each other.

In the Northern Hemisphere, "the Antipodes" may refer to Australia and New Zealand, and Antipodeans to their inhabitants. Geographically, the antipodes of the British Isles are in the Pacific Ocean, south of New Zealand. This gave rise to the name of the Antipodes Islands of New Zealand, which are close to the antipode of London. With the exception of a part of the Perth metropolitan area near Baldivis and Rockingham that is antipodal to Bermuda, the antipodes of Australia are in the North Atlantic Ocean, while parts of Spain, Portugal, France and Morocco are antipodal to New Zealand.

Approximately 15% of land territory is antipodal to other land, representing approximately 4.4% of Earth's surface. Another source estimates that about 3% of Earth's surface is antipodal land. The largest antipodal land masses are the Malay Archipelago, antipodal to the Amazon basin and adjoining Andean ranges; east China and Mongolia, and small sections of southeast Russia, antipodal to Argentina and Chile; and Greenland and the Canadian Arctic Archipelago, antipodal to East Antarctica. There is a general paucity of antipodal land because the Southern Hemisphere has comparatively less land than the Northern Hemisphere and, of that, the antipodes of Australia are in the North Atlantic Ocean, while the antipodes of southern Africa are in the Pacific Ocean.

Geography

Since the antipode of any place on the Earth is the place that is diametrically opposite of it, a line drawn from one to the other will pass through the centre of Earth and form a true diameter. For example, the antipodes of New Zealand's lower North Island lie in Spain. Most of the Earth's land surfaces have ocean at their antipodes; this is a natural consequence of most of the Earth's surface being covered in water.

The antipode of any place on Earth is distant from it by 180° of longitude and as many degrees to the north of the Equator as the original is to the south (or vice versa); in other words, the latitudes are numerically equal, but one is north and the other south. The maps shown here are based on this relationship; they show a Lambert azimuthal equal-area projection of the Earth, in yellow, overlaid on which is another map, in blue, shifted horizontally by 180° of longitude and inverted about the Equator with respect to latitude.

Noon at one place is midnight at the other (ignoring daylight saving time and irregularly shaped time zones) and, with the exception of the tropics, the longest day at one point corresponds to the shortest day at the other, and midwinter at one point coincides with midsummer at the other. Sunrise and sunset do not quite oppose each other at antipodes due to refraction of sunlight.

Mathematical description

If the geographic coordinates (latitude and longitude) of a point on the Earth's surface are (φ, θ), then the coordinates of the antipodal point are (−φ, θ ± 180°). This relation holds true whether the Earth is approximated as a perfect sphere or as a reference ellipsoid.

In terms of the usual way these geographic coordinates are given, this transformation can be expressed symbolically as

x° N/S y° E/W  ↦  x° S/N (180 − y)° W/E,

that is, for the latitude (the north–south coordinate) the magnitude of the angle remains the same but N is changed to S and vice versa, and for the longitude (the East/West coordinate) the angle is replaced by its supplementary angle while E is exchanged for W. For example, the antipode of the point in China at 37° N 119° E (a few hundred kilometres from Beijing) is the point in Argentina at 37° S 61° W (a few hundred kilometres from Buenos Aires).

Etymology

The word antipodes comes from the Greek: ἀντίποδες (antípodes), plural of ἀντίπους (antipous), "with feet opposite (ours)", from ἀντί (antí, “opposite”) + πούς (poús, “foot”). The Greek word is attested in Plato's dialogue Timaeus, already referring to a spherical Earth, explaining the relativity of the terms "above" and "below":

For if there were any solid body in equipoise at the centre of the universe, there would be nothing to draw it to this extreme rather than to that, for they are all perfectly similar; and if a person were to go round the world in a circle, he would often, when standing at the antipodes of his former position, speak of the same point as above and below; for, as I was saying just now, to speak of the whole which is in the form of a globe as having one part above and another below is not like a sensible man.

— Plato

The term is taken up by Aristotle (De caelo 308a.20), Strabo (Geographica 1.1.13), Plutarch (On the Malice of Herodotus 37) and Diogenes Laërtius (Lives and Opinions of Eminent Philosophers book 3), and was adopted into Latin as antipodes. The Latin word changed its sense from the original "under the feet, opposite side" to "those with the feet opposite", i.e. a bahuvrihi referring to hypothetical people living on the opposite side of the Earth. Medieval illustrations imagine them in some way "inverted", with their feet growing out of their heads, pointing upward.

In this sense, Antipodes first entered English in 1398 in a translation of the 13th century De Proprietatibus Rerum by Bartholomeus Anglicus, translated by John of Trevisa:

Yonde in Ethiopia ben the Antipodes, men that haue theyr fete ayenst our fete.

(In Modern English: Yonder in Ethiopia are the Antipodes, men that have their feet against our feet.)

The modern English singular antipode arose in the 16th or 17th century as a back-formation from antipodes; antipous or the Latinate antipus would have been closer to the original singular. Most dictionaries suggest a pronunciation of /ˈæntɪˌpoʊd/ for this form.

Historical significance

Pomponius Mela, the first Roman geographer, asserted that the earth had two habitable zones, a North and South one, but that it would be impossible to get into contact with each other because of the unbearable heat at the Equator (De orbis situ 1.4).

The Terrestrial Sphere of Crates of Mallus (c. 150 BCE), showing the region of the antipodes in the southern half of the western hemisphere

From the time of Augustine of Hippo, the Christian church was skeptical of the notion. Augustine asserted that "it is too absurd to say that some men might have set sail from this side and, traversing the immense expanse of ocean, have propagated there a race of human beings descended from that one first man."

In the Early Middle Ages, Isidore of Seville's widely read encyclopedia presented the term "antipodes" or, as he said "antipodas" as referring to antichthones (people who lived on the opposite side of the Earth), as well as to a geographical place:

Apart from these three parts of the world, there exists a fourth part beyond the interior Ocean; it is in the south and is unknown to us because of the burning heat of the Sun; within its borders the fabled Antipodeans are reputed to dwell.

In using the form antipodas rather than the more usual Latin antipodes Isidore simply transcribed the original Greek αντίποδας, the singular case of the name: the plural case is αντίποδες (antipodes), used in converting the name into Latin. These people came to play a role in medieval discussions about the shape of the Earth.

In 748, in reply to a letter from Boniface, Pope Zachary declared the belief "that beneath the earth there was another world and other men, another sun and moon" to be heretical. In his letter, Boniface had apparently maintained that Vergilius of Salzburg held such a belief.

The antipodes being an attribute of a spherical Earth, some ancient authors used their perceived absurdity as an argument for a flat Earth. However, knowledge of the spherical Earth was widespread during the Middle Ages, only occasionally disputed—the medieval dispute surrounding the antipodes mainly concerned the question whether people could live on the opposite side of the earth: since the torrid clime was considered impassable, it would have been impossible to evangelize them. This posed the problem that Christ told the apostles to evangelize all mankind; with regard to the unreachable antipodes, this would have been impossible. Christ would either have appeared a second time, in the antipodes, or left the damned irredeemable. Such an argument was forwarded by the Spanish theologian Alonso Tostado as late as the 15th century and "St. Augustine doubts" was a response to Columbus's proposal to sail westwards to the Indies.

The author of the Norwegian book Konungs Skuggsjá, from around 1250, discusses the existence of antipodes. He notes that (if they exist) they will see the sun in the north in the middle of the day and that they will have seasons opposite those of the Northern Hemisphere.

Herodotus recorded that Pharaoh Necho II of the 26th Dynasty (610–595 BC) commissioned an expedition of Phoenicians which in three years sailed from the Red Sea around Africa back to the mouth of the Nile, and that "as they sailed on a westerly course round the southern end of Libya (Africa), they had the sun on their right"— to northward of them, proving that they had been in the Southern Hemisphere. The earliest surviving account by a European who had visited the Southern Hemisphere is that of Marco Polo (who, on his way home in 1292, sailed south of the Malay Peninsula). He noted that it was impossible to see the star Polaris from there.

The idea of dry land in the southern climes, the Terra Australis, was introduced by Ptolemy and appears on European maps as an imaginary continent from the 15th century. Antipodes was what Giovanni Contarini, on his world map of 1506 called the land later named America by Martin Waldseemüller. When the land discovered by Pedro Alvarez Cabral in April 1500, Brazil, was formally named Santa Cruz by the assembled Portuguese court on 20 May 1503, it was also referred to in the official record of the proceedings as the “Land of the Antipodes”: terra Antipodum.

The land reached by Columbus in 1492 was identified as that of the Antipodes by the diplomatist Peter Martyr who, in a letter he wrote from Barcelona dated 14 May 1493, said: "A few days since, a certain Christopher Columbus, a Ligurian, returned from the Western Antipodes". Perhaps influenced by this, Fernão Vaz Dourado in his Atlas of 1571 inscribed over the map of Mexico and adjacent parts of America, Tera Antipodum regis Castelle inventa a Xforo Columbo Januensi (Land of the Antipodes, discovered for the King of Castile by Christopher Columbus of Genoa).

In spite of having been discovered relatively late by European explorers, Australia was inhabited very early in human history; the ancestors of the Indigenous Australians reached it at least 50,000 years ago.

True trip "around the world"

To make the longest distance trip around the planet, a traveler would have to pass through a set of antipodal points. All meridians can be crossed in one hemisphere—indeed, this is possible by walking in a several-foot-wide circle around one of the poles—but such trips are shorter than a minimum circumnavigation. On the other hand, the greatest straight line distance that could in theory be covered is a trip exactly on the Equator, a distance of 40,075 kilometres (24,901 mi). The Earth's equatorial bulge makes this slightly longer than a north–south trip around the world along a set of meridian lines, which is a distance of 40,008 kilometres (24,860 mi). Any other closed great circle route starting on the equator and traveling at an angle between 0° (an equatorial route) and 90° (a polar route) would be between 40,075 and 40,008 kilometres (24,901 and 24,860 mi). In all of these cases, after half of the world has been traversed, every subsequent point will be antipodal to one already visited.

Air travel between antipodes

Non-stop antipodal flights by commercial aircraft (scheduled)

There are currently no commercial aircraft capable of traveling non-stop between antipodes with a standard full commercial passenger load.

The current world record-holder Airbus A350-900ULR is capable of flying 18,000 kilometres (9,700 nmi; 11,000 mi), or roughly 90% of an average antipodal distance. Singapore Airlines currently holds the world record for the longest scheduled passenger flight, and utilizes this model in their non-stop Singapore to New York-JFK route SQ23/24.

In 2019, Qantas completed separate non-stop flights taking 19–20 hours to encompass the 16,013 km (9950 miles) from New York and 17,016 km (10,573 miles) from London, both to Sydney, Australia with a limit of 49 passengers on the Boeing 787 Dreamliner and who underwent medical tests on the flight. The London-Sydney direct routes are said to be the world's most profitable ultra-long haul flights annually. Their plans for the same pair of experiments were quickly put on hold due to global travel restrictions throughout the COVID-19 pandemic.

Non-stop antipodal flights by commercial aircraft (chartered)

In March 2021, a Comlux 787-8, registered P4-787, flew a non-scheduled (chartered), non-stop flight from Seoul Incheon to Buenos Aires, which are nearly antipodal points. This set a new record for the longest commercial non-stop flight with paying passengers, covering 19,483 kilometres (10,520 nmi; 12,106 mi) in 20 hours 19 minutes.

The business jet variant of the Airbus A350, the ACJ350, which entered into service in 2020, has a range of 20,550 km (12,770 miles), enabling it to operate between any two available antipodes. As of September 2021, there are three ACJ350s now in service globally. The owner of the first ACJ350, the German Government, has already taken it on a close to antipodal flight with a flight from Cologne, Germany to Canberra, Australia in November 2020. The upcoming Boeing business jet variant, the BBJ 777-8, will also have an antipodal reach with its published range of 21,570 km (13,403 miles). Both aforementioned variants from Airbus and Boeing are the first aircraft designed to handle flights exceeding the Earth's average antipodal distance of 20,000 km (12,420 miles).

Direct flights

Among flights with fuel stop and crew-change stop but still same flight number, Air New Zealand previously had the world's longest active plane route—the Auckland–Los Angeles–London marathon, at 19,240 km (11,960 mi) over Los Angeles (directly 18,360 km or 11,410 mi)—until the airline cancelled this route late in 2019. The current record holder for such a flight is co-owned by Qantas and British Airways in their operating of the Kangaroo Route's Sydney—Singapore—London flights covering a great circle distance of 17,176 km (10,673 mi; 9,274 nmi).

Future theoretical antipodal routes

A hypothetically almost perfect antipodal flight would be Tangier Ibn Battouta Airport, Morocco (IATA: TNG), to Whangarei Aerodrome, New Zealand (IATA: WRE), whose designated locators are 10,800 nautical miles (20,002 km) apart, almost the maximum possible distance. However, with only a length of 3,599 ft (1,097 m), Whangarei's runway is too short to accommodate any current (as of 2015) commercial jet airliner, especially one with the required range. Traveling between them would currently need at least two plane changes.

Other near-antipodal major city pairs include:

List of antipodes

Earth

Some cities and towns which are near-antipodes in equirectangular projection. Blue labels pertain to cyan and brown labels pertain to yellow areas. Areas where cyan and yellow overlap (coloured green) are land antipodes.

Around 71% of the Earth's surface is covered by oceans, and seven-eighths of the Earth's land (when excluding Antarctica) is confined to the land hemisphere, so the majority of locations on land do not have land-based antipodes. About 15% of the earth's land has an antipode on land. Rough calculation shows that, of the 29% of the earth that is covered by land, if 15% of that has antipodes on land, then about 4% (0.15 × 29% = 4.35%) of the earth's surface has antipodes that are both land surfaces. Spilhaus estimates this at about 3%.

The two largest human-inhabited antipodal areas are located in East Asia (mainly eastern China) and South America (mainly Argentina and Chile). The two largest monolithic antipodal land areas are most of Chile and Argentina along with eastern and central China and Mongolia, and most of Greenland along with a part of Antarctica. The Australian mainland is the largest landmass with its antipodes entirely in ocean, although some locations of mainland Australia and Tasmania are close to being antipodes of islands (Bermuda, Azores, Puerto Rico) in the North Atlantic Ocean. The largest landmass with antipodes entirely on land is the island of Borneo, whose antipodes are in the Amazon rainforest.

Cities

Exact or almost exact antipodes:

To within 100 km (62 mi), with at least one major city (population of at least 1 million):

Taiwan (formerly called Formosa) is partly antipodal to the province of Formosa in Argentina.

Capital cities within 200 km (120 mi) of each other's antipodes:

Other major cities or capitals close to being antipodes:

Cities and geographic features

The villages of Alzon, France and Waitangi, New Zealand are an example of antipodal settlements.

Gibraltar is approximately antipodal to Te Ārai about 85 km (53 mi) north of Auckland, New Zealand. This illustrates the old yet correct saying that the sun never sets on the British Empire; the sun still does not set on the Commonwealth of Nations.

The northern part of New Caledonia, an overseas territory of France, is antipodal to some thinly populated desert in Mauritania, a part of the former French West Africa. Portions of Suriname, a former Dutch colony, are antipodal to Sulawesi, an Indonesian island spelled Celebes when it was part of the Netherlands East Indies. Luzon, the largest island of the Philippines, is antipodal to eastern Bolivia. As with the British Empire, the sun set neither on the French Empire, the Dutch Empire, nor the Spanish Empire at their peaks.

Santa Vitória do Palmar, the most southerly town of more than 10,000 people in Brazil, is antipodal to Jeju Island, the southernmost territory of South Korea.

Hawaii is antipodal to parts of Botswana. The Big Island of Hawaii is antipodal to the Okavango Delta in Botswana, with the island's largest city, Hilo, antipodal to Nxai Pan National Park.

Desolate Kerguelen Island is antipodal to an area of thinly inhabited plains on the border between the Canadian provinces of Alberta and Saskatchewan and the US state of Montana. The only permanent settlement on Kerguelen Island, the research station Port-aux-Français, is antipodal to fields 10 km (6.2 mi) northeast of Senate, Saskatchewan. Other Canadian towns with antipodes on Kerguelen Island include: Consul, Nashlyn and Govenlock in the vicinity of Senate, and in Alberta Eagle Butte, Elkwater and Manyberries as well as the Red Coat Trail between Orion, Alberta and Etzikom. The northern part of Liberty County, Montana, especially the communities Goldstone, Fox Crossing and Sage Creek Colony, also have antipodes on Kerguelen Island.

St. Paul Island and Amsterdam Island are antipodal to thinly populated parts of the eastern part of the US state of Colorado. They are situated ca. 10.2 km (6.3 mi) south-south-east of Firstview and 30.5 km (19.0 mi) south-south-west of Granada, Colorado, respectively. Together with the northern part of Liberty County, Montana, they are the only three areas of the Contiguous United States with antipodes on land.

The north-eastern coast of Alaska from Utqiaġvik (former Barrow) over Prudhoe Bay to the Canadian border, and the coasts of the Canadian territories of Yukon, Northwest Territories, and Nunavut, are antipodal to Antarctica.

The Heard Island and McDonald Islands, an uninhabited Australian territory, is antipodal to an area in central Saskatchewan, including the towns of Leask and Shellbrook.

Tigres Island, the largest uninhabited island of Angola, is approximately antipodal to Johnston atoll, which is the third largest uninhabited island of the United States.

Easter Island is antipodal to an area close to Desert National Park, 35 km (22 mi) from Jaisalmer, India. The only town on Easter Island, Hanga Roa, is antipodal to the village of Serawa 46 km (29 mi) northeast of Jaisalmer. Serawa is the only village in India to be antipodal to a human settlement. Its neighbouring villages Mokla and the northern part of Bhadasar also have antipodes on Easter Island. The small, rocky, uninhabited island of Sala y Gómez, 391 km (243 mi) east-northeast of Easter Island, is antipodal to an area in the city of Ajmer, India, just east of Ana Sagar Lake. All the rest of India has its antipodes in the sea.

Kiritimati, the largest island of Kiribati and the largest coral atoll in the world, is antipodal to Salonga National Park, which is the largest national park of the Democratic Republic of the Congo and the largest tropical rainforest reserve in Africa.

Serra da Estrela Natural Park, the largest natural park of Portugal, is antipodal to Kahurangi National Park, the second largest national park of New Zealand.

South Georgia Island is antipodal to the northernmost part of Sakhalin Island.

Lake Baikal is partially antipodal to the Straits of Magellan.

The Russian Antarctic research base Bellingshausen Station is antipodal to a land location in Russian Siberia.

Rottnest Island, off the coast of Western Australia, is approximately antipodal to Bermuda.

Cocos (Keeling) Islands, an Australian external territory in the Indian Ocean, is almost antipodal to Nicaragua's Corn Islands.

Flores Island, the westernmost island of the Azores, is nearly antipodal to Flinders Island between Tasmania and the Australian mainland.

Point Nemo, the point in the South Pacific Ocean most distant from any other land, is precisely opposite a desolate piece of desert in western Kazakhstan.

By definition, the North Pole and the South Pole are antipodes.

Null Island, 0°N 0°E, at the intersection of the prime meridian and the equator, has its antipodes at 0°N 180°E, at the intersection of the antimeridian and the equator. This point lies northeast of Nikunau in the Gilbert Islands and southwest of Baker Island, a United States territory.

As can be seen on the purple/blue map, the Pacific Ocean is so large that it stretches halfway around the world; parts of the Pacific off the coast of Peru are antipodal to parts of the same ocean off the coast of Southeast Asia. For example, the island of Ko Chang—which is the second or third largest island in Thailand—is nearly antipodal to San Lorenzo Island, which is the largest island of Peru.

The antipodes of the Antipodes Islands, considered by early European explorers to be antipodal to the United Kingdom, are the town of Barfleur on France's Cotentin Peninsula.

The remote Pacific atoll of Tematagi is antipodal to the Islamic holy city of Mecca, meaning the direction of Muslim prayer would vary widely from that of surrounding islands.

Angkor Wat is roughly antipodal to Machu Picchu.

Countries

The following countries are opposite more than one other country. (Antarctica is considered separately from any territorial claims.)

Country No. of antipodal countries Antipodal countries
New Zealand 12 Mainland: Spain, Portugal, Morocco, UK (Gibraltar)
Chatham Islands: France
Kermadec Islands: Algeria
Niue: Niger
Tokelau: Nigeria
Cook Islands: Chad, (Penrhyn) Central African Republic, (Mangaia) Libya, (Pukapuka) Cameroon, (Nassau) Nigeria
France 12 Mainland: New Zealand (Chatham Islands)
Southern & Antarctic Lands: Canada, United States
French Guiana: Indonesia
New Caledonia: Mauritania, Western Sahara
Wallis and Futuna: Niger
French Polynesia: Sudan, Egypt, Saudi Arabia, Eritrea, Ethiopia
Brazil 9 China, Japan, South Korea, Philippines, Malaysia, Indonesia, Brunei, Palau, Federated States of Micronesia
Indonesia 8 Ecuador, Peru, Colombia, Venezuela, Brazil, Suriname, Guyana, France (French Guiana)
Peru 7 Vietnam, Cambodia, Laos, Thailand, Malaysia, Indonesia, China
United States 7 Mainland: France (Southern & Antarctic Lands)
Hawaii: Botswana, Namibia
Alaska: Antarctica
Palmyra Atoll & Kingman Reef: DR Congo
American Samoa: Niger, Nigeria
United Kingdom 7 Falklands: China, Russia
Gibraltar: New Zealand
South Georgia and the South Sandwich Islands: Russia
Pitcairn: Saudi Arabia, UAE
Bermuda: Australia
China 6 Argentina, Chile, Uruguay, Brazil, Bolivia, UK (Falkland Islands)
Niger 5 Samoa, Tonga, United States (American Samoa), France (Wallis and Futuna), New Zealand (Niue)
Antarctica 5 Greenland, Canada, United States, Russia, Norway
Argentina 4 China, Taiwan, Mongolia, Russia
Malaysia 4 Ecuador, Peru, Brazil, Colombia
Chile 4 China, Mongolia, Russia; Easter Island: India
Kiribati 4 Phoenix Islands (Orona): Nigeria; Line Islands: DR Congo, Central African Republic, Sudan
Russia 4 Antarctica, Chile, Argentina, United Kingdom (Falklands etc.)
Australia 3 Mainland: Bermuda (UK), Portugal (Azores)
Heard Island and McDonald Islands: Canada
Christmas Island: Colombia
Ecuador 3 Malaysia, Singapore, Indonesia
Philippines 3 Brazil, Bolivia, Paraguay
Vanuatu 3 Mauritania, Senegal, (Mere Lava) Mali
Paraguay 3 Taiwan, Japan, Philippines
Mali 3 Fiji, Vanuatu, Solomon Islands
Colombia 3 Indonesia, Malaysia, Australia (Christmas Island)
Nigeria 3 New Zealand (Tokelau, Cook Ils), United States (American Samoa), Kiribati
Canada 3 Antarctica, France (Kerguelen), Australia (Heard Island and McDonald Islands)
Taiwan 2 Paraguay, Argentina
Tonga 2 Algeria, Niger
Mongolia 2 Chile, Argentina
Tuvalu 2 Ghana, (Nanumanga, Nanumea) Ivory Coast
Fiji 2 Mali; (Rotuma) Burkina Faso
Solomon Islands (Temoto) 2 Guinea, (Tikopia) Mali
Uruguay 2 China, South Korea
Bolivia 2 China, Philippines
Sudan 2 France (French Polynesia), Kiribati
Mauritania 2 France (New Caledonia), Vanuatu
Algeria 2 Tonga, New Zealand (Kermadec)
Central African Republic 2 Kiribati, New Zealand (Cook Ils)
Saudi Arabia 2 France (French Polynesia), UK (Pitcairn)
DR Congo 2 Kiribati, United States (Palmyra, Kingman Reef)
Japan 2 (Ryukyu) Brazil, Paraguay
South Korea 2 Uruguay, Brazil
Norway 2 (Svalbard) Antarctica, (Peter I Island) Russia
Portugal 2 Mainland: New Zealand
Azores: Australia (Melbourne)

Countries matching up with just one other country are Morocco, Spain, Chad, Libya, Cameroon (with the Cook Islands of New Zealand); Egypt, Eritrea, Ethiopia (with French Polynesia); Senegal (Vanuatu); the UAE (Pitcairn); Ghana, Ivory Coast (Tuvalu); Burkina Faso (Rotuma in Fiji); Guinea (Solomon Islands); India (Easter Island); Laos, Cambodia, Vietnam, and Thailand (all with Peru); Singapore (Ecuador); Brunei, Palau, Micronesia (all with Brazil); Venezuela and Suriname (Indonesia).

Of these, the larger countries which are entirely antipodal to land are the Philippines, Malaysia, Taiwan, Fiji, Vanuatu, Brunei, and Samoa. Chile was as well prior to its expansion into the Atacama with the War of the Pacific.

Geological features antipodal to impact basins

In a number of cases on extraterrestrial bodies in the Solar System, unusual geologic features (e.g., jumbled terrain or unique volcanic constructs) are located antipodal to major impact basins. It has been hypothesized that this results from focusing of some of the seismic waves (p-waves and surface waves) produced by an impact at its antipode.

In popular culture

  • In the Shakespeare comedy Much Ado About Nothing, Benedick offers to travel from Messina to the Antipodes in an apparent attempt to avoid the company of Beatrice.
  • On the TV show Angel, the Deeper Well is a hole that goes through the world, with its entrance in the Cotswolds in England and its antipode in New Zealand.
  • At the closing ceremonies of the Rio 2016 Olympics, antipodes were used as a tool to invite viewers to the Tokyo 2020 Olympics, including an image of the video game character Mario using his pipes to travel between Tokyo and Rio, arriving at the closing ceremonies.
  • In the 2012 film Total Recall, a gravity train called "The Fall" goes through the center of the Earth to allow people to commute between Western Europe and Australia.
  • In 2006, Ze Frank challenged viewers of his daily webcast the show with zefrank to create an "Earth sandwich" by simultaneously placing two pieces of bread at antipodal points on the Earth's surface. The challenge was successfully completed by viewers in Spain and New Zealand.
  • The song “Ana Ng” by alternative rock band They Might Be Giants is about someone who believes that their soulmate lives antipodal to them. John Linnell, the singer and songwriter, has since joked that because the name Ng is Vietnamese and Peru is the antipode of Vietnam, “…the song, presumably, is about somebody in Peru, writing about somebody in Vietnam. But I didn’t know that when I wrote it.”
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    Climate of Hawaii

    From Wikipedia, the free encyclopedia
    https://en.wikipedia.org/wiki/Climate_of_Hawaii
    Köppen climate types of Hawaii, using 1971-2000 climate normals.

    The U.S. state of Hawaiʻi, which covers the Hawaiian Islands, is tropical but it experiences many different climates, depending on altitude and surroundings. The island of Hawaiʻi for example hosts 4 (out of 5 in total) climate groups on a surface as small as 4,028 square miles (10,430 km2) according to the Köppen climate types: tropical, arid, temperate and polar. When counting also the Köppen sub-categories – notably including the very rare cold-summer mediterranean climate – the island of Hawaiʻi hosts 10 (out of 14 in total) climate zones. The islands receive most rainfall from the trade winds on their north and east flanks (the windward side) as a result of orographic precipitation. Coastal areas are drier, especially the south and west side or leeward sides.

    Overall with climate change, Hawaiʻi is getting drier and hotter. The Hawaiian Islands receive most of their precipitation from October to April. Drier conditions generally prevail from May to September. Due to cooler waters around Hawaiʻi, the risk of tropical cyclones is low for Hawaiʻi.

    Temperature

    Temperatures at sea level generally range from highs of 84–88 °F (29–31 °C) during the summer months to 79–83 °F (26–28 °C) during the winter months. Rarely does the temperature rise from above 90 °F (32 °C) or drop below 60 °F (16 °C) at lower elevations. Temperatures are lower at higher altitudes. During the winter, snowfall is common at the summits of Mauna Kea and Mauna Loa on Hawaiʻi Island. On Maui, the summit of Haleakalā occasionally experiences snowfall, but snow had never been observed below 7,500 feet (2,300 m) before February 2019, when snow was observed at 6,200 feet (1,900 m) and fell at higher elevations in amounts large enough to force Haleakalā National Park to close for several days. The record low temperature in Honolulu is 52 °F (11 °C) on January 20, 1969.

    Overall with climate change, Hawaiʻi is getting hotter. Temperatures of 90 °F (32 °C) and above are uncommon, with the exception of dry, leeward areas. In the leeward areas, temperatures may reach into the low 90s several days during the year, but temperatures higher than these are unusual. The highest temperature ever recorded on the islands was 100 °F (38 °C) on April 27, 1931, in Pāhala. The surface waters of the open ocean around Hawaiʻi range from 75 °F (24 °C) between late February and early April, to a maximum of 82 °F (28 °C) in late September or early October. In the United States, only Florida has warmer surf temperatures.

    The Pacific High, and with it the trade-wind zone, moves north and south with changing angle of the sun, so that it reaches its northernmost position in the summer. This brings trade winds during the period of May through September, when they are prevalent 80 to 95 percent of the time. From October through April, the heart of the trade winds moves south of Hawaiʻi; thus there average wind speeds are lower across the islands. Due to Hawaiʻi being at the northern edge of the tropics (mostly above 20 latitude), there are only weak wet and dry seasons unlike many tropical climates.

    Winds

    Island wind patterns are very complex. Though the trade winds are fairly constant, their relatively uniform air flow is distorted and disrupted by mountains, hills, and valleys. Usually winds blow upslope by day and downslope by night. Local conditions that produce occasional violent winds are not well understood. These are very localized, sometimes reaching speeds of 60 to 100 mph (100 to 160 km/h) and are best known in the settled areas of Kula and Lāhainā on Maui. The Kula winds are strong downslope winds on the lower slopes of the west side of Haleakalā. These winds tend to be strongest from 2,000 to 4,000 ft (600 to 1,200 m) above mean sea level.

    The Lahaina winds are also downslope winds, but are somewhat different. They are also called "lehua winds" after the ʻōhiʻa lehua (Metrosideros polymorpha), whose red blossoms fill the air when these strong winds blow. They issue from canyons at the base of the western Maui mountains, where steeper canyon slopes meet the more gentle piedmont slope below. These winds only occur every 8 to 12 years. They are extremely violent, with wind speeds of 80–100 mph (130–160 km/h) or more.

    Road to Hāna

    Cloud formation

    Under trade wind conditions, there is very often a pronounced moisture discontinuity between 4,000 and 8,000 feet (1,200 and 2,400 m). Below these heights, the air is moist; above, it is dry. The break (a large-scale feature of the Pacific High) is caused by a temperature inversion embedded in the moving trade wind air. The inversion tends to suppress the vertical movement of air and so restricts cloud development to the zone just below the inversion. The inversion is present 50 to 70 percent of the time; its height fluctuates from day to day, but it is usually between 5,000 and 7,000 feet (1,500 and 2,100 m). On trade wind days when the inversion is well defined, the clouds develop below these heights with only an occasional cloud top breaking through the inversion.

    These towering clouds form along the mountains where the incoming trade wind air converges as it moves up a valley and is forced up and over the mountains to heights of several thousand feet. On days without an inversion, the sky is almost cloudless (completely cloudless skies are extremely rare). In leeward areas well screened from the trade winds (such as the west coast of Maui), skies are clear 30 to 60 percent of the time.

    Windward areas tend to be cloudier during the summer, when the trade winds and associated clouds are more prevalent, while leeward areas, which are less affected by cloudy conditions associated with trade wind cloudiness, tend to be cloudier during the winter, when storm fronts pass through more frequently. On Maui, the cloudiest zones are at and just below the summits of the mountains, and at elevations of 2,000 to 4,000 ft (600 to 1,200 m) on the windward sides of Haleakalā. In these locations the sky is cloudy more than 70 percent of the time. The usual clarity of the air in the high mountains is associated with the low moisture content of the air.

    Precipitation

    Hawaiʻi differs from many tropical locations with pronounced wet and dry seasons, in that the wet season coincides with the winter months (rather than the summer months more typical of other places in the tropics). For instance, Honolulu's Köppen climate classification is the rare As wet-winter subcategory of the tropical wet and dry climate type.

    Overall with climate change, Hawaiʻi is getting drier. Major storms occur most frequently in October through March. There may be as many as six or seven major storm events in a year. Such storms bring heavy rains and can be accompanied by strong local winds. The storms may be associated with the passage of a cold front, the leading edge of a mass of relatively cool air that is moving from west to east or from northwest to southeast.

    Annual mean rainfall ranges from 7.4 in (188 mm) on the summit of Mauna Kea to 404.4 in (10,271 mm) in Big Bog. Windward slopes have greater rainfall than leeward lowlands and tall mountains.

    Average Annual Rainfall for the State of Hawaiʻi, http://rainfall.geography.hawaii.edu/

    On windward coasts, many brief showers are common, not one of which is heavy enough to produce more than 0.01 in (0.25 mm) of rain. The usual run of trade wind weather yields many light showers in the lowlands, whereas torrential rains are associated with a sudden surge in the trade winds or with a major storm. Hāna has had as much as 28 in (710 mm) of rain in a single 24-hour period.

    Severe thunderstorms, as defined by the National Weather Service (NWS) as tornadoes, hail 1 in (25 mm) or larger, and/or convective winds of at least 58 mph (93 km/h) occur but are relatively uncommon. Nontornadic waterspouts are more common than tornadoes produced by supercells, which produce stronger, longer lasting tornadoes, especially with respect to inland areas, and also produce the largest hail, such as the 2012 Hawaiʻi hailstorm. An annual average of approximately one tornado, either emanating from supercells or by other processes, occurs.

    Kona storms are features of the winter season. The name comes from winds out of the "kona" or usually leeward direction. Rainfall in a well-developed Kona storm is widespread and more prolonged than in the usual cold-front storm. Kona storm rains are usually most intense in an arc, extending from south to east of the storm and well in advance of its center. Kona rains last from several hours to several days. The rains may continue steadily, but the longer lasting ones are characteristically interrupted by intervals of lighter rain or partial clearing, as well as by intense showers superimposed on the more moderate continuous, steady rain. An entire winter may pass without a single well-developed Kona storm. More often there are one or two such storms a year; sometimes four or five.

    Hurricanes

    Main article: List of Hawaii hurricanes

    The hurricane season in the Hawaiian Islands is roughly from June through November, when hurricanes and tropical storms are most probable in the North Pacific. These storms tend to originate off the coast of Mexico (particularly the Baja California peninsula) and track west or northwest towards the islands. As storms cross the Pacific, they tend to lose strength if they bear northward and encounter cooler water.

    True hurricanes are rare in Hawaiʻi, thanks in part to the comparatively cool waters around the islands as well as unfavorable atmospheric conditions, such as enhanced wind shear; only four have affected the islands during 63 years. Tropical storms are more frequent. These have more modest winds, below 74 mph (119 km/h). Because tropical storms resemble Kona storms, and because early records do not distinguish clearly between them, it has been difficult to estimate the average frequency of tropical storms. Every year or two a tropical storm will affect the weather in some part of the islands. Unlike cold fronts and Kona storms, hurricanes and tropical storms are most likely to occur during the last half of the year, from July through December. Three strong and destructive hurricanes are known to have made landfall on the islands, an unnamed storm in 1871, Hurricane Dot in 1959, and Hurricane ʻIniki in 1992. Another hurricane, ʻIwa, caused significant damage in 1982 but its center passed nearby and did not directly make landfall. The rarity of hurricanes making landfall on the Islands is subject to change as the climate warms. In the Pliocene era, where CO2 levels were comparable to those we see today, the waters around Hawaiʻi were much warmer, resulting in frequent hurricane strikes in computer simulations.

    Effect on trade winds

    A true-color satellite view of Hawaiʻi shows that most of the flora on the islands grow on the north-east sides, which face the trade winds. The texture change around the calmer south-west of the islands is the result of the shelter provided from the islands.
     
    The top image above shows the winds around the Hawaiian Islands measured by the Seawinds instrument aboard QuikSCAT during August 1999. Trade winds blow from right to left in the image. The bottom image shows the ocean current formed by the islands’ wake. Arrows indicate current direction and speed, while white contours show ocean temperatures. The warm water of the current generates winds that sustain the current for thousands of miles.

    Despite being small islands within the vast Pacific Ocean, the Hawaiian Islands have a surprising effect on ocean currents and circulation patterns over much of the Pacific. In the Northern Hemisphere, trade winds blow from northeast to southwest, from North and South America toward Asia, between the equator and 30 degrees north latitude. Typically, the trade winds continue across the Pacific, unless something gets in their way, like an island.

    Hawaiʻi's high mountains present a substantial obstacle to the trade winds. The elevated topography blocks the airflow, effectively splitting the trade winds in two. This split causes a zone of weak winds, called a "wind wake", on the leeward side of the islands.

    Aerodynamic theory indicates that an island wind wake effect should dissipate within a few hundred kilometers and not be felt in the western Pacific. However, the wind wake caused by the Hawaiian Islands extends 1,860 miles (3,000 km), roughly 10 times longer than any other wake. The long wake testifies to the strong interaction between the atmosphere and ocean, which has strong implications for global climate research. It is also important for understanding natural climate variations, like El Niño.

    There are number of reasons why this has been observed only in Hawaiʻi. First, the ocean reacts slowly to fast-changing winds; winds must be steady to exert force on the ocean, such as the trade winds. Second, the high mountain topography provides a significant disturbance to the winds. Third, the Hawaiian Islands are large in horizontal (east-west) scale, extending over four degrees in longitude. It is this active interaction between wind, ocean current, and temperature that creates this uniquely long wake west of Hawaiʻi.

    The wind wake drives an eastward "counter current" that brings warm water 5,000 miles (8,000 km) from the Asian coast. This warm water drives further changes in wind, allowing the island effect to extend far into the western Pacific. The counter current had been observed by oceanographers near the Hawaiian Islands years before the long wake was discovered, but they did not know what caused it.

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    Hawaiian Islands

    From Wikipedia, the free encyclopedia
    https://en.wikipedia.org/wiki/Hawaiian_Islands

    The Hawaiian Islands (Hawaiian: Nā Moku o Hawai‘i) are an archipelago of eight major volcanic islands, several atolls, and numerous smaller islets in the North Pacific Ocean, extending some 1,500 miles (2,400 kilometers) from the island of Hawaiʻi in the south to northernmost Kure Atoll. Formerly called the Sandwich Islands, the present name for the archipelago is derived from the name of its largest island, Hawaiʻi.

    The archipelago sits on the Pacific Plate. The islands are exposed peaks of a great undersea mountain range known as the Hawaiian–Emperor seamount chain, formed by volcanic activity over a hotspot in the Earth's mantle. The islands are about 1,860 miles (3,000 km) from the nearest continent and are part of the Polynesia subregion of Oceania.

    The U.S. state of Hawaii occupies the archipelago almost in its entirety (including the mostly uninhabited Northwestern Hawaiian Islands), with the sole exception of Midway Atoll (a United States Minor Outlying Island). Hawaii is the only U.S. state that is situated entirely on an archipelago, and the only state not geographically connected with North America. The Northwestern islands (sometimes called the Leeward Islands) and surrounding seas are protected as a National Monument and World Heritage Site.

    Islands and reefs

    Main article: History of Hawaii

    The date of the first settlements of the Hawaiian Islands is a topic of continuing debate. Archaeological evidence seems to indicate a settlement as early as 124 AD.

    Captain James Cook, RN, visited the islands on January 18, 1778, and named them the "Sandwich Islands" in honor of The 4th Earl of Sandwich, who as the First Lord of the Admiralty was one of his sponsors. This name was in use until the 1840s, when the local name "Hawaii" gradually began to take precedence.

    The Hawaiian Islands have a total land area of 6,423.4 square miles (16,636.5 km2). Except for Midway, which is an unincorporated territory of the United States, these islands and islets are administered as Hawaii—the 50th state of the United States.

    Major islands

    Island Nickname Area Population
    (as of 2020)     		Density Highest point Maximum Elevation Age (Ma) Location
    Hawaiʻi The Big Island 4,028.0 sq mi (10,432.5 km2) 200,629 49.8/sq mi (19.2/km2) Mauna Kea 13,796 ft (4,205 m) 0.4 19°34′N 155°30′W
    Maui The Valley Isle 727.2 sq mi (1,883.4 km2) 164,221 225.8/sq mi (87.2/km2) Haleakalā 10,023 ft (3,055 m) 1.3–0.8 20°48′N 156°20′W
    Oʻahu The Gathering Place 596.7 sq mi (1,545.4 km2) 1,016,508 1,703.5/sq mi (657.7/km2) Mount Kaʻala 4,003 ft (1,220 m) 3.7–2.6 21°28′N 157°59′W
    Kauaʻi The Garden Isle 552.3 sq mi (1,430.5 km2) 73,298 132.7/sq mi (51.2/km2) Kawaikini 5,243 ft (1,598 m) 5.1 22°05′N 159°30′W
    Molokaʻi The Friendly Isle 260.0 sq mi (673.4 km2) 7,345 28.3/sq mi (10.9/km2) Kamakou 4,961 ft (1,512 m) 1.9–1.8 21°08′N 157°02′W
    Lānaʻi The Pineapple Isle 140.5 sq mi (363.9 km2) 3,367 24.0/sq mi (9.3/km2) Lānaʻihale 3,366 ft (1,026 m) 1.3 20°50′N 156°56′W
    Niʻihau The Forbidden Isle 69.5 sq mi (180.0 km2) 84 1.2/sq mi (0.5/km2) Mount Pānīʻau 1,250 ft (381 m) 4.9 21°54′N 160°10′W
    Kahoʻolawe The Target Isle 44.6 sq mi (115.5 km2) 0 0/sq mi (0/km2) Puʻu Moaulanui 1,483 ft (452 m) 1.0 20°33′N 156°36′W

    The eight major islands of Hawaii (Windward Islands) are listed above. All except Kaho'olawe are inhabited.

    Minor islands, islets

    Hawaiian Islands from space.
    3-D perspective view of the southeastern Hawaiian Islands, with the white summits of Mauna Loa (4,170 m or 13,680 ft high) and Mauna Kea (4,207.3 m or 13,803 ft high). The islands are the tops of massive volcanoes, the bulk of which lie below the sea surface. Ocean depths are colored from violet (5,750 m or 18,860 ft deep northeast of Maui) and indigo to light gray (shallowest). Historical lava flows are shown in red, erupting from the summits and rift zones of Mauna Loa, Kilauea, and Hualalai volcanoes on Hawaiʻi.

    The state of Hawaii counts 137 "islands" in the Hawaiian chain. This number includes all minor islands (small islands), islets (even smaller islands) offshore of the major islands (listed above) and individual islets in each atoll. These are just a few:

    Partial islands, atolls, reefs

    A composite satellite image from NASA of the Hawaiian Islands taken from outer space. Click on the image for a larger view that shows the main islands and the extended archipelago.

    Partial islands, atolls, reefs (west of Niʻihau are uninhabited except Midway Atoll) form the Northwestern Hawaiian Islands (Leeward Islands):

    Geology

    Main article: Hawaii hotspot
    See also: List of Hawaii rivers
    Eruptions from the Hawaii hotspot left a trail of underwater mountains across the Pacific over millions of years, called the Emperor Seamounts.

    This chain of islands, or archipelago, developed as the Pacific Plate slowly moved northwestward over a hotspot in the Earth's mantle at a rate of approximately 32 miles (51 km) per million years. Thus, the southeast island is volcanically active, whereas the islands on the northwest end of the archipelago are older and typically smaller, due to longer exposure to erosion. The age of the archipelago has been estimated using potassium-argon dating methods. From this study and others, it is estimated that the northwesternmost island, Kure Atoll, is the oldest at approximately 28 million years (Ma); while the southeasternmost island, Hawaiʻi, is approximately 0.4 Ma (400,000 years). The only active volcanism in the last 200 years has been on the southeastern island, Hawaiʻi, and on the submerged but growing volcano to the extreme southeast, Kamaʻehuakanaloa (formerly Loʻihi). The Hawaiian Volcano Observatory of the USGS documents recent volcanic activity and provides images and interpretations of the volcanism. Kīlauea had been erupting nearly continuously since 1983 when it stopped August 2018.

    Almost all of the magma of the hotspot has the composition of basalt, and so the Hawaiian volcanoes are composed almost entirely of this igneous rock. There is very little coarser-grained gabbro and diabase. Nephelinite is exposed on the islands but is extremely rare. The majority of eruptions in Hawaiʻi are Hawaiian-type eruptions because basaltic magma is relatively fluid compared with magmas typically involved in more explosive eruptions, such as the andesitic magmas that produce some of the spectacular and dangerous eruptions around the margins of the Pacific basin.

    Hawaiʻi island (the Big Island) is the biggest and youngest island in the chain, built from five volcanoes. Mauna Loa, taking up over half of the Big Island, is the largest shield volcano on the Earth. The measurement from sea level to summit is more than 2.5 miles (4 km), from sea level to sea floor about 3.1 miles (5 km).

    Earthquakes

    Main article: List of earthquakes in Hawaii

    The Hawaiian Islands have many earthquakes, generally triggered by and related to volcanic activity. Seismic activity, as a result, is currently highest in the southern part of the chain. Both historical and modern earthquake databases have correlated higher magnitude earthquakes with flanks of active volcanoes, such as Mauna Loa and Kilauea. The combination of erosional forces, which cause slumping and landslides, with the pressure exerted by rising magma put a great amount of stress on the volcanic flanks. The stress is released when the slope fails, or slips, causing an earthquake. This type of seismicity is unique because the forces driving the system are not always consistent over time, since rates of volcanic activity fluctuate. Seismic hazard near active, seaward volcanic flanks is high, partially due to the especially unpredictable nature of the forces that trigger earthquakes, and partially because these events occur at relatively shallow depths. Flank earthquakes typically occur at depths ranging from 5 to 20 km, increasing the hazard to local infrastructure and communities. Earthquakes and landslides on the island chain have also been known to cause tsunamis.

    Most of the early earthquake monitoring took place in Hilo, by missionaries Titus Coan, Sarah J. Lyman and her family. Between 1833 and 1896, approximately 4 or 5 earthquakes were reported per year. Today, earthquakes are monitored by the Hawaiian Volcano Observatory run by the USGS.

    Hawaii accounted for 7.3% of the United States' reported earthquakes with a magnitude 3.5 or greater from 1974 to 2003, with a total 1533 earthquakes. Hawaii ranked as the state with the third most earthquakes over this time period, after Alaska and California.

    On October 15, 2006, there was an earthquake with a magnitude of 6.7 off the northwest coast of the island of Hawaii, near the Kona area of the big island. The initial earthquake was followed approximately five minutes later by a magnitude 5.7 aftershock. Minor-to-moderate damage was reported on most of the Big Island. Several major roadways became impassable from rock slides, and effects were felt as far away as Honolulu, Oahu, nearly 150 miles (240 km) from the epicenter. Power outages lasted for several hours to days. Several water mains ruptured. No deaths or life-threatening injuries were reported.

    On May 4, 2018, there was a 6.9 earthquake in the zone of volcanic activity from Kīlauea.

    Earthquakes are monitored by the Hawaiian Volcano Observatory run by the USGS.

    Tsunamis

    Aftermath of the 1960 Chilean tsunami in Hilo, Hawaiʻi, where the tsunami left 61 people dead and 282 seriously injured. The waves reached 35 feet (11 m) high.

    The Hawaiian Islands are subject to tsunamis, great waves that strike the shore. Tsunamis are most often caused by earthquakes somewhere in the Pacific. The waves produced by the earthquakes travel at speeds of 400–500 miles per hour (600–800 km/h) and can affect coastal regions thousands of miles (kilometers) away.

    Tsunamis may also originate from the Hawaiian Islands. Explosive volcanic activity can cause tsunamis. The island of Molokaʻi had a catastrophic collapse or debris avalanche over a million years ago; this underwater landslide likely caused tsunamis. The Hilina Slump on the island of Hawaiʻi is another potential place for a large landslide and resulting tsunami.

    The city of Hilo on the Big Island has been most affected by tsunamis, where the in-rushing water is accentuated by the shape of Hilo Bay. Coastal cities have tsunami warning sirens.

    A tsunami resulting from an earthquake in Chile hit the islands on February 27, 2010. It was relatively minor, but local emergency management officials utilized the latest technology and ordered evacuations in preparation for a possible major event. The Governor declared it a "good drill" for the next major event.

    A tsunami resulting from an earthquake in Japan hit the islands on March 11, 2011. It was relatively minor, but local officials ordered evacuations in preparation for a possible major event. The tsunami caused about $30.1 million in damages.

    Volcanos

    Main article: List of volcanoes in the Hawaiian–Emperor seamount chain
    Lava erupting from Kīlauea, one of six active volcanoes in the Hawaiian islands. Kīlauea is the most active, erupting nearly continuously from 1983 to 2018.

    Only the two Hawaiian islands furthest to the southeast have active volcanoes: Haleakalā on Maui, and Mauna Loa, Mauna Kea, Kilauea, and Hualalai, all on the Big Island. The volcanoes on the remaining islands are extinct as they are no longer over the Hawaii hotspot. The Kamaʻehuakanaloa Seamount is an active submarine volcano that is expected to become the newest Hawaiian island when it rises above the ocean's surface in 10,000–100,000 years. Hazards from these volcanoes include lava flows that can destroy and bury the surrounding surface, volcanic gas emissions, earthquakes and tsunamis listed above, submarine eruptions affecting the ocean, and the possibility of an explosive eruption.

    History

    Main article: History of Hawaii

    There is no definitive date for the Polynesian discovery of Hawaii. However, high-precision radiocarbon dating in Hawaii using chronometric hygiene analysis, and taxonomic identification selection of samples, puts the initial such settlement of the Hawaiian Islands sometime between 1219 and 1266 A.D., originating from earlier settlements first established in the Society Islands around 1025 to 1120 A.D., and in the Marquesas Islands sometime between 1100 and 1200 A.D.

    An expedition led by British explorer James Cook is usually considered to be the first group of Europeans to arrive in the Hawaiian Islands, which they did in 1778. However, Spanish historians and some other researchers state that the Spanish captain Ruy López de Villalobos was the first European to see the islands in 1542. The Spanish named these islands "Isla de Mesa, de los Monjes y Desgraciada" (1542), being on the route linking the Philippines with Mexico across the Pacific Ocean, between the ports of Acapulco and Manila, which were both part of New Spain. Within five years after Cook's arrival, European military technology helped Kamehameha I, ruler of the island of Hawaii, conquer and unify the islands for the first time, establishing the Kingdom of Hawaii in 1795. The kingdom was prosperous and important for its agriculture and strategic location in the Pacific.

    American immigration, led by Protestant missionaries, and Native Hawaiian emigration, mostly on whaling ships, began almost immediately after Cook's arrival. Americans set up plantations to grow sugar. Their methods of plantation farming required substantial labor. Waves of permanent immigrants came from Japan, China, and the Philippines to work in the fields. The government of Japan organized and gave special protection to its people, who comprised about 25 percent of the Hawaiian population by 1896. The Hawaiian monarchy encouraged this multi-ethnic society, initially establishing a constitutional monarchy in 1840 that promised equal voting rights regardless of race, gender, or wealth.

    The population of Native Hawaiians in Hawaii declined from an unknown number prior to 1778 (commonly estimated to be around 300,000), to around 142,000 in the 1820s based on the first census conducted by American missionaries, 82,203 in the 1850 Hawaiian Kingdom census, 40,622 in the last Hawaiian Kingdom census of 1890, 39,504 in the only census by the Republic of Hawaii in 1896, and 37,656 in the first census conducted by the United States in 1900 after the annexation of Hawaii to the United States in 1898. Since Hawaii has joined the United States the Native Hawaiian population in Hawaii has increased with every census to 289,970 in 2010.

    Americans within the kingdom government rewrote the constitution, severely curtailing the power of King "David" Kalākaua, and disenfranchising the rights of most Native Hawaiians and Asian citizens to vote, through excessively high property and income requirements. This gave a sizeable advantage to plantation owners. Queen Liliʻuokalani attempted to restore royal powers in 1893 but was placed under house arrest by businessmen with help from the United States military. Against the Queen's wishes, the Republic of Hawaii was formed for a short time. This government agreed on behalf of Hawaii to join the United States in 1898 as the Territory of Hawaii. In 1959, the islands became the state of Hawaii.

    Ecology

    See also: Endemism in the Hawaiian Islands, List of animal species introduced to the Hawaiian Islands, and List of invasive plant species in Hawaii

    The islands are home to a multitude of endemic species. Since human settlement, first by Polynesians, non native trees, plants, and animals were introduced. These included species such as rats and pigs, that have preyed on native birds and invertebrates that initially evolved in the absence of such predators. The growing population of humans has also led to deforestation, forest degradation, treeless grasslands, and environmental degradation. As a result, many species which depended on forest habitats and food became extinct—with many current species facing extinction. As humans cleared land for farming, monocultural crop production replaced multi-species systems.

    'I'iwi (Drepanis coccinea) and other endemic species have been heavily impacted by human activity, such as invasive species and habitat loss.

    The arrival of the Europeans had a more significant impact, with the promotion of large-scale single-species export agriculture and livestock grazing. This led to increased clearing of forests, and the development of towns, adding many more species to the list of extinct animals of the Hawaiian Islands. As of 2009, many of the remaining endemic species are considered endangered.

    National Monument

    On June 15, 2006, President George W. Bush issued a public proclamation creating Papahānaumokuākea Marine National Monument under the Antiquities Act of 1906. The Monument encompasses the northwestern Hawaiian Islands and surrounding waters, forming the largest marine wildlife reserve in the world. In August 2010, UNESCO's World Heritage Committee added Papahānaumokuākea to its list of World Heritage Sites. On August 26, 2016, President Barack Obama greatly expanded Papahānaumokuākea, quadrupling it from its original size.

    Climate

    Main article: Climate of Hawaii

    The Hawaiian Islands are tropical but experience many different climates, depending on altitude and surroundings. The islands receive most rainfall from the trade winds on their north and east flanks (the windward side) as a result of orographic precipitation. Coastal areas in general and especially the south and west flanks, or leeward sides, tend to be drier.

    In general, the lowlands of Hawaiian Islands receive most of their precipitation during the winter months (October to April). Drier conditions generally prevail from May to September. The tropical storms, and occasional hurricanes, tend to occur from July through November.

    During the summer months the average temperature is about 84 °F (29 °C), in the winter months it is approximately 79 °F (26 °C). As the temperature is relatively constant over the year the probability of dangerous thunderstorms is approximately low.

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