The thrust faults responsible for megathrust earthquakes often lie at the bottom of oceanic trenches;
in such cases, the earthquakes can abruptly displace the sea floor over
a large area. As a result, megathrust earthquakes often generate tsunamis that are considerably more destructive than the earthquakes themselves. Teletsunamis can cross ocean basins to devastate areas far from the original earthquake.
Terminology and mechanism
Diagram of a subduction zone. The megathrust fault lies on the top of the subducting slab where it is in contact with the overriding plate.
The term megathrust refers to an extremely large thrust fault, typically formed at the plate interface along a subduction zone, such as the Sunda megathrust. However, the term is also occasionally applied to large thrust faults in continental collision zones, such as the Himalayan megathrust. A megathrust fault can be 1,000 kilometers (600 mi) long.
Cross-sectional illustration of normal and reverse faults
A thrust fault is a type of reverse fault,
in which the rock above the fault is displaced upwards relative to the
rock below the fault. This distinguishes reverse faults from normal faults, where the rock above the fault is displaced downwards, or strike-slip faults,
where the rock on one side of the fault is displaced horizontally with
respect to the other side. Thrust faults are distinguished from other
reverse faults because they dip at a relatively shallow angle, typically
less than 45°, and show large displacements.In effect, the rocks above the fault have been thrust over the rocks
below the fault. Thrust faults are characteristic of areas where the Earth's crust is being compressed by tectonic forces.
Megathrust faults occur where two tectonic plates collide. When one of the plates is composed of oceanic lithosphere, it dives beneath the other plate (called the overriding plate) and sinks into the Earth's mantle as a slab.
The contact between the colliding plates is the megathrust fault, where
the rock of the overriding plate is displaced upwards relative to the
rock of the descending slab.
Friction along the megathrust fault can lock the plates together, and
the subduction forces then build up strain in the two plates. A
megathrust earthquake takes place when the fault ruptures, allowing the
plates to abruptly move past each other to release the accumulated
strain energy.
Megathrust earthquakes are almost exclusive to tectonic subduction zones and are often associated with the Pacific and Indian Oceans. These subduction zones are also largely responsible for the volcanic activity associated with the Pacific Ring of Fire.
Since these earthquakes deform the ocean floor, they often generate strong tsunami waves. Subduction zone earthquakes are also known to produce intense shaking and ground movements that can last for up to 3-5 minutes.
In the Indian Ocean region, the Sunda megathrust is located where the Indo-Australian Plate subucts under the Eurasian Plate along a 5,500 kilometres (3,400 mi) fault off the coasts of Myanmar, Sumatra, Java and Bali, terminating off the northwestern coast of Australia. This subduction zone was responsible for the 2004 Indian Ocean earthquake and tsunami. In parts of the megathrust south of Java, referred to as the Java Trench, for the western part, Mw 8.9 is possible, while in the eastern Java segment, Mw 8.8 is possible, while if both were to rupture at the same time, the magnitude would be Mw 9.1.
In the South China Sea lies the Manila Trench, which is capable of producing Mw 9.0 or larger earthquakes, with the maximum magnitude at Mw 9.2 or higher.
In North America, the Juan de Fuca Plate subducts under the North American Plate, creating the Cascadia subduction zone from mid Vancouver Island, British Columbia down to Northern California. This subduction zone was responsible for the 1700 Cascadia earthquake. The Aleutian Trench, of the southern coast of Alaska and the Aleutian Islands, where the North American Plate overrides the Pacific Plate, has generated many major earthquakes throughout history, several of which generated Pacific-wide tsunamis, including the 1964 Alaska earthquake;
at magnitude 9.1–9.2, it remains the largest recorded earthquake in
North America, and the third-largest earthquake instrumentally recorded
in the world.
In the Himalayan region, where the Indian Plate subducts under the Eurasian Plate, the largest recorded earthquake was the 1950 Assam–Tibet earthquake,
at magnitude 8.7. It is estimated that earthquakes with magnitude 9.0
or larger are expected to occur at an interval of every 800 years, with
the highest boundary being a magnitude 10, though this is not considered
physically possible. Therefore, the largest possible earthquake in the
region is a magnitude 9.7, assuming a single rupture of the whole
Himalayan arc and assuming standard scaling law, which implies an
average slip of 50 m.
A megathrust earthquake could occur in the Lesser Antilles subduction zone, with a maximum magnitude of 9.3, or potentially even 10.3 through recent evaluations, a value not considered impossible.
The largest recorded megathrust earthquake was the 1960 Valdivia earthquake, estimated between magnitudes 9.4–9.6, centered off the coast of Chile along the Peru-Chile Trench, where the Nazca Plate subducts under the South American Plate. This megathrust region has regularly generated extremely large earthquakes.
The largest possible earthquakes are estimated at magnitudes of 10 to 11, most likely caused by a combined rupture of the Japan Trench and Kuril–Kamchatka Trench, or individually the Aleutian Trench or Peru–Chile Trench.Another possible area could be the Lesser Antilles subduction zone.
A study reported in 2016 found that the largest megathrust quakes
are associated with downgoing slabs with the shallowest dip, so-called flat slab subduction.
Compared with other earthquakes of similar magnitude, megathrust
earthquakes have a longer duration and slower rupture velocities. The
largest megathrust earthquakes occur in subduction zones with thick
sediments, which may allow a fault rupture to propagate for great
distances unimpeded.
The ACS is a leading source of scientific information through its
peer-reviewed scientific journals, national conferences, and the Chemical Abstracts Service. Its publications division produces over 80 scholarly journals including the prestigious Journal of the American Chemical Society, as well as the weekly trade magazine Chemical & Engineering News.
The ACS holds national meetings twice a year covering the complete
field of chemistry and also holds smaller conferences concentrating on
specific chemical fields or geographic regions. The primary source of
income of the ACS is the Chemical Abstracts Service, a provider of chemical databases worldwide.
The ACS has student chapters in virtually every major university in the United States and outside the United States as well.
These student chapters mainly focus on volunteering opportunities,
career development, and the discussion of student and faculty research.
The organization also publishes textbooks, administers several national
chemistry awards, provides grants for scientific research, and supports
various educational and outreach activities.
The ACS has been criticized for predatory pricing of its products (SciFinder, journals and other publications), for opposing open access
publishing, as well as for initiating numerous copyright enforcement
litigations, often with meaningless outcomes, despite its non-profit
status and its chartered commitment to dissemination of chemical
information.
History
American Chemical Society headquarters in Washington, D.C.
Creation
In 1874, a group of American chemists gathered at the Joseph Priestley House to mark the 100th anniversary of Priestley's discovery of oxygen. Although there was an American scientific society at that time (the American Association for the Advancement of Science, founded in 1848), the growth of chemistry
in the U.S. prompted those assembled to consider founding a new society
that would focus more directly on theoretical and applied chemistry.
Two years later, on April 6, 1876, during a meeting of chemists at the
University of the City of New York (now New York University) the American Chemical Society was founded. The society received its charter of incorporation from the State of New York in 1877.
Charles F. Chandler, a professor of chemistry at Columbia University
who was instrumental in organizing the society said that such a body
would "prove a powerful and healthy stimulus to original research, ...
would awaken and develop much talent now wasting in isolation, ...
[bring] members of the association into closer union, and ensure a
better appreciation of our science and its students on the part of the
general public."
Although Chandler was a likely choice to become the society's first president because of his role in organizing the society, New York University chemistry professor John William Draper was elected as the first president of the society because of his national reputation. Draper was a photochemist and pioneering photographer who had produced one of the first photographic portraits in 1840.[8] Chandler would later serve as president in 1881 and 1889.
In the ACS logo, originally designed in the early 20th century by Tiffany's Jewelers and used since 1909, a stylized symbol of a kaliapparat is used.
Growth
The Journal of the American Chemical Society
was founded in 1879 to publish original chemical research. It was the
first journal published by ACS and is still the society's flagship
peer-reviewed publication. In 1907, Chemical Abstracts was established
as a separate journal (it previously appeared within JACS), which later
became the Chemical Abstracts Service, a division of ACS that provides chemical information to researchers and others worldwide. Chemical & Engineering News is a weekly trade magazine that has been published by ACS since 1923.
The society adopted a new constitution aimed at nationalizing the organization in 1890. In 1905, the American Chemical Society moved from New York City to Washington, D.C. ACS was reincorporated under a congressional charter in 1937. It was granted by the U.S. Congress and signed by president Franklin D. Roosevelt. ACS's headquarters moved to its current location in downtown Washington in 1941.
Organization
Divisions
ACS
first established technical divisions in 1908 to foster the exchange of
information among scientists who work in particular fields of chemistry
or professional interests. Divisional activities include organizing
technical sessions at ACS meetings, publishing books and resources,
administering awards and lectureships, and conducting other events. The
original five divisions were 1) organic chemistry, 2) industrial
chemists and chemical engineers, 3) agricultural and food chemistry, 4)
fertilizer chemistry, and 5) physical and inorganic chemistry.
As of 2016, there are 32 technical divisions of ACS.
This is the largest division of the Society. It marked its 100th anniversary in 2008. The first Chair of the Division was Edward Curtis Franklin. The Organic Division played a part in establishing Organic Syntheses, Inc. and Organic Reactions, Inc. and it maintains close ties to both organizations.
The Division's best known activities include organizing symposia
(talks and poster sessions) at the biannual ACS National Meetings, for
the purpose of recognizing promising Assistant Professors, talented
young researchers, outstanding technical contributions from junior-level
chemists, in the field of organic chemistry. The symposia also honor national award winners, including the Arthur C. Cope Award,
Cope Scholar Award, James Flack Norris Award in Physical Organic
Chemistry, Herbert C. Brown Award for Creative Research in Synthetic
Methods.
The Division helps to organize symposia at the international meeting called Pacifichem and it organizes the biennial National Organic Chemistry Symposium (NOS) which highlights recent advances in organic chemistry and hosts the Roger Adams Award address. The Division also organizes corporate sponsorships to provide fellowships for PhD students and undergraduates. It also organizes the Graduate Research Symposium and manages award and travel grant programs for undergraduates.
Local sections
Local
sections were authorized in 1890 and are autonomous units of the
American Chemical Society. They elect their own officers and select
representatives to the national ACS organization. Local sections also
provide professional development opportunities for members, organize
community outreach events, offer awards, and conduct other business. The Rhode Island Section was the first local section of ACS, organized in 1891.
There are currently 186 local sections of the American Chemical Society
in all 50 states, the District of Columbia, and Puerto Rico.
International Chemical Sciences Chapters
International
Chemical Sciences Chapters allow ACS members outside of the U.S. to
organize locally for professional and scientific exchange. There are currently 24 International Chemical Sciences Chapters.
ACS
states that it offers teacher training to support the professional
development of science teachers so they can better present chemistry in
the classroom, foster the scientific curiosity of our nation's youth and
encourage future generations to pursue scientific careers. As of 2009,
Clifford and Kathryn Hach
donated $33 million to ACS, to continue the work of the Hach Scientific
Foundation in supporting high school chemistry teaching.
The ACS Division of Chemical Education provides standardized tests for various subfields of chemistry.
The two most commonly used tests are the undergraduate-level tests for
general and organic chemistry. Each of these tests consists of 70
multiple-choice questions, and gives students 110 minutes to complete
the exam.
The ACS also approves certified undergraduate programs in
chemistry. A student who completes the required laboratory and course
work—sometimes in excess of what a particular college may require for
its Bachelor's degree—is considered by the Society to be well trained for professional work.
The ACS coordinates two annual public awareness campaigns, National Chemistry Week
and Chemists Celebrate Earth Week, as part of its educational outreach.
Since 1978 and 2003 respectively, the campaigns have been celebrated
with a yearly theme, such as "Chemistry Colors Our World" (2015) and
"Energy: Now and Forever!" (2013).
Green Chemistry Institute
The Green Chemistry Institute (GCI) supports the "implementation of green chemistry and engineering throughout the global chemistry enterprise."
The GCI organizes an annual conference, the Green Chemistry and
Engineering Conference, provides research grants, administers awards,
and provides information and support for green chemistry practices to
educators, researchers, and industry.
The GCI was founded in 1997 as an independent non-profit organization, by chemists Joe Breen and Dennis Hjeresen in cooperation with the Environmental Protection Agency. In 2001, the GCI became a part of the American Chemical Society.
Petroleum Research Fund
The
Petroleum Research Fund (PRF) is an endowment fund administered by the
ACS that supports advanced education and fundamental research in the
petroleum and fossil fuel fields at non-profit institutions. Several categories of grants are offered for various career levels and institutions. The fund awarded more than $25 million in grants in 2007.
The PRF traces its origins to the acquisition of the Universal Oil Products laboratory by a consortium of oil companies in 1931.
The companies established a trust fund, The Petroleum Research Fund, in
1944 to prevent antitrust litigation tied to their UOP assets. The ACS
was named the beneficiary of the trust. The first grants from the PRF
were awarded in 1954. In 2000, the trust was transferred to the ACS. The
ACS established The American Chemical Society Petroleum Research Fund
and the previous trust was dissolved. The PRF trust was valued at $144.7 million in December 2014.
Other programs
The
ACS International Activities is the birthplace of the ACS International
Center, an online resource for scientists and engineers looking to
study abroad or explore an international career or internship. The site
houses information on hundreds of scholarships and grants related to all
levels of experience to promote scientific mobility of researchers and
practitioners in STEM fields.
The Society grants membership to undergraduates as student
members provided they can pay the $25 yearly dues. Any university may
start its own ACS Student Chapter and receive benefits of undergraduate
participation in regional conferences and discounts on ACS publications.
The American Chemical Society administers 64 national awards, medals
and prizes based on scientific contributions at various career levels
that promote achievement across the chemical sciences. The ACS national awards program began in 1922 with the establishment of the Priestley Medal, the highest award offered by the ACS, which is given for distinguished services to chemistry. The 2019 recipient of the Priestley Medal is K. Barry Sharpless.
Other awards
Additional awards are offered by divisions, local sections and other bodies of ACS. The William H. Nichols Medal Award
was the first ACS award to honor outstanding researchers in the field
of chemistry. It was established in 1903 by the ACS New York Section and
is named for William H. Nichols, an American chemist and businessman and one of the original founders of ACS. Of the over 100 Nichols Medalists, 16 have subsequently been awarded the Nobel Prize in Chemistry. The Willard Gibbs Award, granted by the ACS Chicago Section, was established in 1910 in honor of Josiah Willard Gibbs, the Yale University professor who formulated the phase rule.
The Georgia Local Section of ACS has awarded the Herty Medal since 1933 recognizing outstanding chemists who have significantly contributed to their chosen fields.
All chemists in academic, government, or industrial laboratories who
have been residing in the southeastern United States for at least 10
years are eligible.
The New York Section of ACS also gives Leadership Awards.
The Leadership Awards are the highest honors given by the Chemical
Marketing and Economic Group of ACS NY since December 6, 2012. They are
presented to leaders of industry, investments, and other sectors, for
their contributions to science, technology, engineering and mathematics
(STEM) initiatives. Honorees include Andrew N. Liveris (Dow Chemical), P. Roy Vagelos (Regeneron, Merck), Thomas M. Connelly (DuPont) and Juan Pablo del Valle (Mexichem).
The ACS also administers regional awards presented annually at
regional meetings. This includes the E. Ann Nalley Regional Award for
Volunteer Service to the American Chemical Society, Regional Awards for
Excellence in High School Teaching, and the Stanley C. Israel Regional
Award for Advancing Diversity in the Chemical Sciences.
ACS Publications is the publishing division of the ACS. It is a nonprofit academic publisher of scientific journals
covering various fields of chemistry and related sciences. As of 2021,
ACS Publications published the following peer-reviewed journals:
In addition to academic journals, ACS Publications also publishes Chemical & Engineering News, a weekly trade magazine covering news in the chemical profession, inChemistry, a magazine for undergraduate students, and ChemMatters, a magazine for high school students and teachers.
In
debates about free access to scientific information, the ACS has been
described as "in an interesting dilemma, with some of its
representatives pushing for open access and others hating the very
thought."
The ACS has generally opposed legislation that would mandate free
access to scientific journal articles and chemical information. However
it has recently launched new open access journals
and provided authors with open access publishing options. Nevertheless,
the actual percentage of open-access publications in ACS journals is
the lowest among the 8 major scientific journal publishers (see figure
below):
Open access by year according to Web of Science
Journals
The
mid-2000s saw a debate between some research funders (including the
federal government), which argued that research they funded should be
presented freely to the public,
and some publishers (including the ACS), which argued that the costs of
peer-review and publishing justified their subscription prices. In 2006, Congress debated legislation that would have instructed the National Institutes of Health (NIH) to require all investigators it funded to submit copies of final, peer-reviewed journal articles to PubMed Central, a free-access digital repository it operates, within 12 months of publication. At the time the American Association of Publishers (of which ACS is a member) hired a public relations firm to counter the open access movement. In spite of publishers' opposition, the PubMed Central legislation was passed in December 2007 and became effective in 2008.
As the open access issue has continued to evolve, so too has the ACS's position. In response to a 2013 White House Office of Science and Technology Policy
directive that instructed federal agencies to provide greater access to
federally funded research, the ACS joined other scholarly publishers in
establishing the Clearinghouse for the Open Research of the United
States (Chorus) to allow free access to published articles.
The ACS has also introduced several open access publishing options for
its journals, including providing authors the option to pay an upfront
fee to enable free online access to their articles. In 2015, the ACS launched the first fully open access journal in the society's history, ACS Central Science.
The ACS states that the journal offers the same peer-review standards
as its subscription journals, but without publishing charges to either
authors or readers. A second open access title, ACS Omega, an interdisciplinary mega journal, launched in 2016.In December 2020, the ACS launched a series of 9 open access journals under the name ACS Au (chemical symbol for gold) which include
ACS Bio & Med Chem Au,
ACS Engineering Au,
ACS Environmental Au,
ACS Materials Au,
ACS Measurement Science Au,
ACS Nanoscience Au,
ACS Organic & Inorganic Au,
ACS Physical Chem Au and
ACS Polymers Au.
Databases
In 2005, the ACS was criticized for opposing the creation of PubChem, which is an open accesschemical database developed by the NIH's National Center for Biotechnology Information.
The ACS raised concerns that the publicly supported PubChem database
would duplicate and unfairly compete with their existing fee-based Chemical Abstracts Service
and argued that the database should only present data created by the
Molecular Libraries Screening Center initiative of the NIH.
The ACS lobbied members of the United States Congress to rein in PubChem and hired outside lobbying firms to try to persuade congressional members, the NIH, and the Office of Management and Budget (OMB) against establishing a publicly funded database. The ACS was unsuccessful, and as of 2012 PubChem is the world's largest free chemical database.
The ACS is also the only provider of a major scientific publication database (SciFinder) that imposes a restriction on the number of records that can be exported. None of the competing products, such as Web of Science (owned by Clarivate), Scopus (owned by Elsevier) and The Lens (owned by Cambia) has similar restrictions.
Litigations
The
ACS has been involved in numerous lawsuits regarding access to its
databases, trademark rights, and copyrighted material. In many of these
cases, the ACS lost or ended up with an unenforceable judgement. These
include:
Dialogv. American Chemical Society, a suit claiming antitrust violations in access to ACS databases, settled out of court in 1993;,
American Chemical Society v. Google, a suit claiming trademark violation, settled out of court in 2006;
American Chemical Society v. Leadscope, a suit alleging
stolen trade secrets, concluded in 2012 with ACS losing its trade
secrets claim and Leadscope losing its counterclaim of defamation;
against ResearchGate, where a German court refused to award monetary compensation to the ACS and Elsevier;
against Sci-Hub, which resulted in a non-enforceable judgement.
The ACS was also found guilty in several lawsuits brought against the Society by its employees.
Executive compensation
In
2004, a group of ACS members criticized the compensation of former
executive director and chief executive officer John Crum, whose total
salary, expenses, and bonuses for 2002 was reported to be $767,834. The ACS defended the figure, saying that it was in line with that of comparable organizations, including for-profit publishers.
As of 2016, two employees were reported to have a total compensation exceeding $900,000, while 694 had a compensation exceeding $100,000.
Federally funded research and development centers (FFRDCs) are public-private partnerships that conduct research and development for the United States Government. Under Federal Acquisition Regulation§ 35.017,
FFRDCs are operated by universities and corporations to fulfill certain
long-term needs of the government that "...cannot be met as effectively
by existing in-house or contractor resources." While similar in many
ways to University Affiliated Research Centers, FFRDCs are prohibited from competing for work. There are currently 42 FFRDCs, each sponsored by one or more U.S. government departments or agencies.
History
Since
the 1960s, private businesses in the U.S. have provided an increasing
share of funding for research and development, as direct federal funding
waned.
During World War II
scientists, engineers, mathematicians, and other specialists became
part of the massive United States war effort—leading to evolutions in
radar, aircraft, computing and, most famously, the development of
nuclear weapons through the Manhattan Project. The end of armed conflict did not end the need for organized research and development in support of the government.
As the Cold War
became the new reality, government officials and their scientific
advisors advanced the idea of a systematic approach to research,
development, and acquisitions—one independent of the ups and downs of
the marketplace and free of the restrictions on civil service. From this
idea arose the concept of FFRDCs—private entities that would work
almost exclusively on behalf of the government—free of organizational
conflicts of interest and with a stable workforce of highly trained
technical talent.
The U.S. Air Force created the first FFRDC, the RAND Corporation, in 1947. Others grew directly out of their wartime roles. For example, MIT Lincoln Laboratory,
founded in 1951, originated as the Radiation Laboratory at MIT, and the
Navy's Operation Research Group evolved into the Center for Naval
Analyses. The first FFRDCs served the Department of Defense.
Since then, other government organizations have sponsored FFRDCs to
meet their specific needs. In 1969, the number of FFRDCs peaked at 74.
