Amelia E. Shevenell | |
---|---|
Alma mater | Hamilton College University of California, Santa Barbara |
Scientific career | |
Institutions | University of Washington University of South Florida |
Doctoral advisor | James P. Kennett |
Website | https://ameliashevenell.wordpress.com/ |
Amelia E. Shevenell is an American marine geologist who specializes in high-latitude paleoclimatology and paleoceanography. She is currently a Professor in the College of Marine Science at the University of South Florida. She has made notable contributions to understanding the history of the Antarctic ice sheets and published in high-impact journals and, as a result, was awarded full membership of Sigma Xi. She has a long record of participation in international ocean drilling programs and has served in leadership positions of these organizations. Shevenell served as the elected Geological Oceanography Council Member for The Oceanography Society (2019-2021). [1]
Shevenell earned a bachelor's degree in geology and studio art at Hamilton College in New York State. Shevenell worked as a laboratory technician and environmental scientist in Juneau, Alaska, before attending the University of California, Santa Barbara, where she studied Antarctic ice sheet evolution and paleoceanography and earned her Ph.D. in Marine Science (2004). Shevenell was a postdoctoral fellow at the Program on Climate Change at the University of Washington School of Oceanography. From 2007 to 2011, Shevenell was a lecturer in earth sciences and geography at University College London. In 2011, Shevenell joined the faculty of the University of South Florida College of Marine Science, earning tenure in 2017. [2]
Amelia Shevenell's research focuses on understanding the evolution of Antarctica's ice sheets over the last 65 million years. Shevenell uses the sedimentological, geochemical, and micropaleontological properties of marine sediments from the deep-sea and Antarctica's continental margins to reconstruct relationships between Antarctica's ice sheets and Earth's oceans, carbon cycle, and climate on million - to decadal timescales. Shevenell's research is relevant to Intergovernmental Panel on Climate Change (IPCC) concerns that ongoing oceanic and atmospheric warming is accelerating polar ice cap melting and global sea level rise. She has participated in eight oceanographic expeditions to the Southern Ocean, several of which are featured in her scientific blogs.
Antarctic ice sheet development during the Cenozoic. Shevenell's research has focused on Antarctic ice sheet development in the Miocene when ice expansion occurred. Her work discovered that Southern Ocean cooling during the Middle Miocene Climate Transition occurred before the expansion of Antarctica's ice sheets at ~14 million years ago. [3] Shevenell has since shown that progressive ice sheet expansion on Antarctica began around 14.8 million years ago, during the Miocene Climatic Optimum, when average global temperatures were warmer than present. Ice growth was paced by changes the eccentricity of Earth's orbit around the Sun. [4] [5] [6] Another study established that glaciers reached the Sabrina Coast of East Antarctica by at least the late Paleocene to early Eocene. [7] This finding was counter to earlier studies that placed the beginning of ice expansion in Antarctica at the start of the Oligocene roughly 34 million years ago. [8] [9]
Carbon cycling in high-latitude oceans. In a study of Holocene marine sediments in the western Pacific Shevenell found evidence for increased upwelling in the North Pacific. [10] The increased upwelling was caused by stronger winds, which in turn released more CO2 into the atmosphere enhancing global warming during the Holocene and the shrinkage of ice sheets. Thus, demonstrating that a possible cause of the warming was a change in ocean circulation. [10]
Holocene ocean temperature and climate evolution of the western Antarctic Peninsula. TEX86 proxy analysis of sediments from the western Antarctic Peninsula continental shelf documented the changing influence of warm Circumpolar Deep Water on regional glacier and sea ice extent since the last deglaciation, ~13,000 years ago. Cooling rather than warming occurred, driven by changes in local solar irradiance associated with changes in Earth's orbit. [11] At present, atmospheric connections to the tropical Pacific allow warm ocean waters to move onto Antarctica's continental shelves, melting regional glaciers. Shevenell's research indicates this process has occurred in past warm climate intervals, and will likely continue as Earth's climate continues to warm. [11]
Participation in scientific ocean drilling. Shevenell is involved in scientific ocean drilling and has worked both as an onshore laboratory scientist and twice as a shipboard scientist on seven Ocean Drilling Program/International Ocean Discovery Program (ODP/IODP) expeditions. She participated as a sedimentologist on ODP Leg 189 to the South Tasman Rise. This expedition tested the hypothesis that Antarctic Ice Sheets developed in association with the development of the Southern Ocean and the Antarctic Circumpolar Current. [12] Shevenell led the sedimentology group on IODP Expedition 374 to the central Ross Sea, Antarctica. This Expedition was designed to understand the factors influencing ice sheet development over the last 20 million years, including the formation and history of the West Antarctic Ice Sheet. [13]
Shevenell has also served within the leadership of the IODP Scientific Advisory Structure, as a member of the Science Evaluation Panel [14] (2011-2014) [15] and the United States Advisory Committee for Scientific Ocean Drilling [16] (2014-2018). [17] Shevenell has served as a US member of the JOIDES Resolution facility board since 2019.
In 2006, Shevenell was awarded the Storrs Cole Memorial Research Award of the Geological Society of America for her publications on invertebrate micropaleontology. [18]
Based upon her scientific ocean drilling research, Shevenell was selected as an IODP Distinguished Lecturer for 2014–2015. [19] Lecturers are nominated by the scientific ocean drilling community and selected by the United States Science Support Office for ocean drilling. Distinguished lecturers visit institutions that are not typically involved in ocean drilling and may not have funds to host visiting speakers.
In 2016, Shevenell was recognized by American Geophysical Union (AGU) journal editors as an AGU Outstanding Reviewer for Geophysical Research Letters . [20]
In 2019, Shevenell was elected as a Full Member of Sigma Xi, the scientific research honor society. [21]
Her Nature paper, Gulick and Shevenell et al. [7] was featured as a cover image by the journal and highlighted in its News and Views section. [22]
The significance of Shevenall's work to the understanding of changes affecting the Antarctic ice sheets have been featured in Discover Magazine, [23] National Geographic , [24] and Reuters. [25]
Her research is featured in an episode of the Forecast Podcast [26] a podcast about climate science and climate scientists with Nature’s editor for climate science, Michael White.
Shevenell also maintains a blog for Antarctic research cruises on ice breaker Laurence Gould LMG12-11 (October, 2012); LMG13-11 (October 2013); icebreaker Nathaniel Palmer NBP14-02 (January–March, 2014), and IODP Expedition 374 (January–March, 2018). [27]
The Antarctic is a polar region around Earth's South Pole, opposite the Arctic region around the North Pole.
The Eocene is a geological epoch that lasted from about 56 to 33.9 million years ago (Ma). It is the second epoch of the Paleogene Period in the modern Cenozoic Era. The name Eocene comes from the Ancient Greek ἠώς and καινός and refers to the "dawn" of modern ('new') fauna that appeared during the epoch.
The Miocene is the first geological epoch of the Neogene Period and extends from about 23.03 to 5.333 million years ago (Ma). The Miocene was named by Scottish geologist Charles Lyell; the name comes from the Greek words μείων and καινός and means "less recent" because it has 18% fewer modern marine invertebrates than the Pliocene has. The Miocene is preceded by the Oligocene and is followed by the Pliocene.
The Pliocene is the epoch in the geologic time scale that extends from 5.333 million to 2.58 million years ago. It is the second and most recent epoch of the Neogene Period in the Cenozoic Era. The Pliocene follows the Miocene Epoch and is followed by the Pleistocene Epoch. Prior to the 2009 revision of the geologic time scale, which placed the four most recent major glaciations entirely within the Pleistocene, the Pliocene also included the Gelasian Stage, which lasted from 2.588 to 1.806 million years ago, and is now included in the Pleistocene.
The Ross Sea is a deep bay of the Southern Ocean in Antarctica, between Victoria Land and Marie Byrd Land and within the Ross Embayment, and is the southernmost sea on Earth. It derives its name from the British explorer James Clark Ross who visited this area in 1841. To the west of the sea lies Ross Island and Victoria Land, to the east Roosevelt Island and Edward VII Peninsula in Marie Byrd Land, while the southernmost part is covered by the Ross Ice Shelf, and is about 200 miles (320 km) from the South Pole. Its boundaries and area have been defined by the New Zealand National Institute of Water and Atmospheric Research as having an area of 637,000 square kilometres (246,000 sq mi).
The climate of Antarctica is the coldest on Earth. The continent is also extremely dry, averaging 166 mm (6.5 in) of precipitation per year. Snow rarely melts on most parts of the continent, and, after being compressed, becomes the glacier ice that makes up the ice sheet. Weather fronts rarely penetrate far into the continent, because of the katabatic winds. Most of Antarctica has an ice-cap climate with extremely cold and dry weather.
The Deep Sea Drilling Project (DSDP) was an ocean drilling project operated from 1968 to 1983. The program was a success, as evidenced by the data and publications that have resulted from it. The data are now hosted by Texas A&M University, although the program was coordinated by the Scripps Institution of Oceanography at the University of California, San Diego. DSDP provided crucial data to support the seafloor spreading hypothesis and helped to prove the theory of plate tectonics. DSDP was the first of three international scientific ocean drilling programs that have operated over more than 40 years. It was followed by the Ocean Drilling Program (ODP) in 1985, the Integrated Ocean Drilling Program in 2004 and the present International Ocean Discovery Program in 2013.
Dansgaard–Oeschger events, named after palaeoclimatologists Willi Dansgaard and Hans Oeschger, are rapid climate fluctuations that occurred 25 times during the last glacial period. Some scientists say that the events occur quasi-periodically with a recurrence time being a multiple of 1,470 years, but this is debated. The comparable climate cyclicity during the Holocene is referred to as Bond events.
Paleoceanography is the study of the history of the oceans in the geologic past with regard to circulation, chemistry, biology, geology and patterns of sedimentation and biological productivity. Paleoceanographic studies using environment models and different proxies enable the scientific community to assess the role of the oceanic processes in the global climate by the re-construction of past climate at various intervals. Paleoceanographic research is also intimately tied to paleoclimatology.
The Nordenskjöld Coast is located on the Antarctic Peninsula, more specifically Graham Land, which is the top region of the Peninsula. The Peninsula is a thin, long ice sheet with an Alpine-style mountain chain. The coast consists of 15m tall ice cliffs with ice shelves.
The Eocene–Oligocene extinction event, also called the Eocene-Oligocene transition (EOT) or Grande Coupure, is the transition between the end of the Eocene and the beginning of the Oligocene, an extinction event and faunal turnover occurring between 33.9 and 33.4 million years ago. It was marked by large-scale extinction and floral and faunal turnover, although it was relatively minor in comparison to the largest mass extinctions.
Timothy Raymond Naish is a New Zealand glaciologist and climate scientist who has been a researcher and lecturer at Victoria University of Wellington and the Director of the Antarctic Research Centre, and in 2020 became a programme leader at the Antarctic Science Platform. Naish has researched and written about the possible effect of melting ice sheets in Antarctica on global sea levels due to high CO2 emissions causing warming in the Southern Ocean. He was instrumental in establishing and leading the Antarctica Drilling Project (ANDRILL), and a Lead Author on the Intergovernmental Panel on Climate Change (IPCC) 5th Assessment Report (2014).
The Middle Miocene Climatic Transition (MMCT) was a relatively steady period of climatic cooling that occurred around the middle of the Miocene, roughly 14 million years ago (Ma), during the Langhian stage, and resulted in the growth of ice sheet volumes globally, and the reestablishment of the ice of the East Antarctic Ice Sheet (EAIS). The term Middle Miocene disruption, alternatively the Middle Miocene extinction or Middle Miocene extinction peak, refers to a wave of extinctions of terrestrial and aquatic life forms that occurred during this climatic interval. This period was preceded by the Middle Miocene Climatic Optimum (MMCO), a period of relative warmth from 18 to 14 Ma. Cooling that led to the Middle Miocene disruption is primarily attributed CO2 being pulled out of the Earth's atmosphere by organic material before becoming caught in different locations like the Monterey Formation. These may have been amplified by changes in oceanic and atmospheric circulation due to continental drift. Additionally, orbitally paced factors may also have played a role.
Antarctica is Earth's southernmost and least-populated continent. Situated almost entirely south of the Antarctic Circle and surrounded by the Southern Ocean, it contains the geographic South Pole. Antarctica is the fifth-largest continent, being about 40% larger than Europe, and has an area of 14,200,000 km2 (5,500,000 sq mi). Most of Antarctica is covered by the Antarctic ice sheet, with an average thickness of 1.9 km (1.2 mi).
Christina Riesselman is an American paleoceanographer whose research focus is on Southern Ocean response to changing climate.
Carlota Escutia Dotti is a Spanish geologist, best known for her work on the geologic evolution of Antarctica and the global role of the Antarctic ice cap. Escutia is based at the Instituto Andaluz de Ciencias de la Tierra, Universidad de Granada and the High Council for Scientific Research (CSIC).
Bruce Peter Luyendyk is an American geophysicist and oceanographer, currently professor emeritus of marine geophysics at the University of California, Santa Barbara. His work spans marine geology of the major ocean basins, the tectonics of southern California, marine hydrocarbon seeps, and the tectonics and paleoclimate of Antarctica. His research includes tectonic rotations of the California Transverse Ranges, participation in the discovery of deep-sea hydrothermal vents, quantitative studies of marine hydrocarbon seeps, and geologic exploration of the Ford Ranges in Marie Byrd Land, Antarctica.
The Late Cenozoic Ice Age, or Antarctic Glaciation, began 34 million years ago at the Eocene-Oligocene Boundary and is ongoing. It is Earth's current ice age or icehouse period. Its beginning is marked by the formation of the Antarctic ice sheets.
Robert Murray McKay is a paleoceanographer who specialises in sedimentology, stratigraphy and palaeoclimatology, specifically gathering geological evidence to study how marine-based portions of the Antarctic ice sheet behave in response to abrupt climate and oceanic change. He has been involved in examination of marine sedimentary records and glacial deposits to show melting and cooling in Antarctica over the past 65 million years and how this has influenced global sea levels and climate. This has helped climate change scientists overcome uncertainty about how the ice sheets will respond to global warming and how this can be managed effectively in the 21st century. He has participated in international projects including ANDRILL and the International Ocean Discovery Program (IODP), led major New Zealand government-funded research teams and has received several awards in recognition of his work. Since 2023 McKay has been a full professor at Victoria University of Wellington and from 2019, director of the Antarctic Research Centre.
Global paleoclimate indicators are the proxies sensitive to global paleoclimatic environment changes. They are mostly derived from marine sediments. Paleoclimate indicators derived from terrestrial sediments, on the other hand, are commonly influenced by local tectonic movements and paleogeographic variations. Factors governing the Earth's climate system include plate tectonics, which controls the configuration of continents, the interplay between the atmosphere and the ocean, and the Earth's orbital characteristics. Global paleoclimate indicators are established based on the information extracted from the analyses of geologic materials, including biological, geochemical and mineralogical data preserved in marine sediments. Indicators are generally grouped into three categories; paleontological, geochemical and lithological.
{{cite journal}}
: CS1 maint: multiple names: authors list (link) CS1 maint: numeric names: authors list (link)