Research overview
Sims is a National Geographic explorer well known for using his technical mountaineering skills to collect geological samples from remote locations across the globe, including sampling molten magma from lava lakes deep within volcanic craters, collecting temporal sequences of lavas from high, technical ridges on the flanks of the world's tallest volcanoes, and using submersibles to obtain mid-ocean ridge basalts from the bottom of the Earth's oceans. [2] Many of these adventures have been featured in National Geographic publications and documentaries, as well as numerous other media venues. [3] [4] [5] [6]
Sims’ research endeavors focus on obtaining hard-to-collect samples and then measuring unique and analytically challenging isotope systems to provide otherwise unobtainable answers to societally relevant questions about Earth systems science. Sims’ research applies a variety of isotopic techniques (U– and Th– decay series, cosmogenic nuclides, radiogenic isotopes, and non-traditional stable isotopes) to address a wide range of topics in earth and ocean sciences. Sims has published nearly one hundred research articles in peer-reviewed scientific journals, including Nature and Science [7] . These publications cover a wide range of topics: magma genesis, differentiation, and degassing; continental and oceanic crustal construction; planetary accretion and core formation; trace-element partitioning; surficial weathering; paleo-oceanography; chemical oceanography; ground water hydrology; water-rock interaction; fumarolic activity; volcanic aerosol formation and dispersal; serpentinization; natural rates of carbon sequestration; and, shallow subsurface geophysics. Sims’ major contributions are determining the time scales and dynamics of magma genesis and volcanic processes.
Sims’ research is funded by the US National Science Foundation, National Geographic Society, the US Department of Energy, Woods Hole Oceanographic Institution and the University of Wyoming.
Career
Sims received a B.A. in geology in 1986 from Colorado College, graduating lllCum lllLaude with llHonors. [8] He completed an M.Sc. at the University of New Mexico’s Institute of Meteoritics [9] in 1989, where his research focused on chemical fractionation during the formation of the Earth’s core and continental crust. His Ph.D. was earned in 1995 from the University of California, Berkeley [10] where his research focused on magma genesis in the Earth’s mantle. Sims worked as a student and then as a guest scientist for the Isotope and Nuclear Chemistry Group at the Los Alamos National Laboratory, New Mexico. [11] After completing his Ph.D., Sims was awarded the Woods Hole Oceanographic Institution (WHOI) Postdoctoral Scholar Fellow from 1995-1997. He was then hired onto the WHOI scientific staff in 1997 where he remained as a tenured research scientist until 2009. In 2009 Sims moved to the department of geology and geophysics of the University of Wyoming, where he is now a full professor. [12] Sims was a Visiting CNRS Fellow at the Institut Universitaire Européen de la Mer (IUEM), France in 2002. [13] In 2016, Sims became a US Fulbright scholar and a visiting professor at the Instituto de Geofisico, Escuela Politécnica Nacional, Quito Ecuador. [14] In his current role at the University of Wyoming, Sims is involved in a variety of research projects, graduate and undergraduate teaching, and the supervision of graduate students. [15] Sims is the University of Wyoming Organizational Lead for the Yellowstone Volcano Observatory. [16] Sims has received various academic accolades for his research and public engagement. [17]
Additionally, Sims worked as a professional climbing instructor and high-altitude mountaineering guide for 23 years (1975-1998) including in Antarctica, Alaska, Mexico and Peru. During this period, he pioneered many difficult first ascents around the world.
Field work
Sims’ field work, primarily funded by the National Geographic Society and the National Science Foundation (NSF), has crossed the globe from the bottom of the Earth's oceans to the top of its highest volcanoes. Highlights of Sims’ field research include:
Antarctica
Sims has been to Antarctica fourteen times since 1989. He has worked both as a guide for science parties funded by the NSF and NASA (including as a guide and rigger for the NASA Dante Rover project [18] ), and also as a principal investigator funded by the NSF to conduct research on the volcanoes of Ross Island and Mt Morning. In particular, Sims has worked and published extensively on Mt Erebus, the world's southernmost active volcano, including descending into its active crater numerous times to collect recently erupted lava bombs from its persistent lava lake. Sims’ most recent expeditions (2012–2017) have been to study the volcanoes Mt Bird, Mt Terror and Hut Point on Ross Island and also the volcanic cones on Mt Discovery. [19]
Democratic Republic of the Congo
Sims’ expeditions to the Democratic Republic of the Congo were funded by the National Geographic Society to film two documentaries and by NSF for research related to volcano hazard assessment. In his research pursuits, Sims has trekked deep into the Virunga jungles to access the remote, and often active volcano Nyamulagira, and he repeatedly descended into the active Nyamulagira crater to collect old lava flows from the crater walls and molten magma from the active lava lake. [20]
Ecuador
Sims has conducted numerous expeditions into the Ecuadorian volcanoes. Funded by the National Geographic Society in 2014, Sims led a month-long expedition into the remote Sangay volcano (5,300 meters/17,400 feet ASL), which is one of the highest and most continuously active volcanoes in the world. In 2016, while living in Ecuador for six months on a US Fulbright Scholarship, Sims conducted several two-week expeditions to collect samples on the steep, glacially dissected flanks and high-altitude ridges of Chimborazo (6,263 meters/20,548 feet ASL). Sims has also conducted and published NSF- and UW-funded research on the volcanoes Reventador, Sumaco, and the Chalupas Caldera.
Mid-ocean ridges
Sims has researched the petrology of mid-ocean ridges extensively. Sims worked on several research expeditions to 9-10°N East Pacific Rise aboard the WHOI operated Research Vessel (RV) Atlantis [21] utilizing the U.S. Navy-owned Deep Submergence Vehicle (DSV) Alvin [22] and other remotely operated (DSL-120 and Jason) and autonomous (ABE) vehicles to conduct his research. Sims has also sent his graduate students on research expeditions to the Kolbeinsey Ridge, the SW Indian Ridge, 45°N Mid Atlantic Ridge, and 9°03 East Pacific Rise.
Yellowstone
Wyoming is home to one of the world's super-volcanos, Yellowstone, which also happens to host the world's most profound, and visually stunning example of an active continental hydrothermal system. Since moving to Wyoming, Sims has been coordinating the introduction of novel geochemical and geophysical techniques to study Yellowstone's “geohydrobiology”, which is the study of how Earth, water and life connect.
Other locations
Sims’ research has also taken him to volcanoes in Italy (Mt. Etna and Stromboli), Nicaragua (Vulcan Masaya), Iceland (Hekla, Theistareykir, Krafla), Hawaii (Kilauea, Mauna Loa, Hualalai, Mauna Kea and Haleakala), and New Mexico (Jemez Volcanic Field, Zuni-Bandera, and Raton-Clayton Volcanic Field). Sims has worked on problems related to serpentinization and carbonization in Samail Ophiolite of Oman, and the Josephine Peridotite in Oregon.
The Samoan archipelago is a chain of 16 islands and numerous seamounts covering 3,123 km2 (1,206 sq mi) in the central South Pacific, south of the equator, about halfway between Hawaii and New Zealand, forming part of Polynesia and of the wider region of Oceania. The islands are Savaiʻi, Upolu, Tutuila, ’Uvea, Taʻū, Ofu, Olosega, Apolima, Manono, Nuʻutele, Niulakita, Nuʻulua, Namua, Fanuatapu, Rose Atoll, Nu'ulopa, as well as the submerged Vailuluʻu, Pasco banks, and Alexa Bank.
Basalt is an aphanitic (fine-grained) extrusive igneous rock formed from the rapid cooling of low-viscosity lava rich in magnesium and iron exposed at or very near the surface of a rocky planet or moon. More than 90% of all volcanic rock on Earth is basalt. Rapid-cooling, fine-grained basalt is chemically equivalent to slow-cooling, coarse-grained gabbro. The eruption of basalt lava is observed by geologists at about 20 volcanoes per year. Basalt is also an important rock type on other planetary bodies in the Solar System. For example, the bulk of the plains of Venus, which cover ~80% of the surface, are basaltic; the lunar maria are plains of flood-basaltic lava flows; and basalt is a common rock on the surface of Mars.
The Yellowstone Caldera, sometimes referred to as the Yellowstone Supervolcano, is a volcanic caldera and supervolcano in Yellowstone National Park in the Western United States. The caldera and most of the park are located in the northwest corner of the state of Wyoming. The caldera measures 43 by 28 miles, and postcaldera lavas spill out a significant distance beyond the caldera proper.
A xenolith is a rock fragment that becomes enveloped in a larger rock during the latter's development and solidification. In geology, the term xenolith is almost exclusively used to describe inclusions in igneous rock entrained during magma ascent, emplacement and eruption. Xenoliths may be engulfed along the margins of a magma chamber, torn loose from the walls of an erupting lava conduit or explosive diatreme or picked up along the base of a flowing body of lava on the Earth's surface. A xenocryst is an individual foreign crystal included within an igneous body. Examples of xenocrysts are quartz crystals in a silica-deficient lava and diamonds within kimberlite diatremes. Xenoliths can be non-uniform within individual locations, even in areas which are spatially limited, e.g. rhyolite-dominated lava of Niijima volcano (Japan) contains two types of gabbroic xenoliths which are of different origin - they were formed in different temperature and pressure conditions.
The Sunda Arc is a volcanic arc that produced the volcanoes that form the topographic spine of the islands of Sumatra, Nusa Tenggara, Java, the Sunda Strait, and the Lesser Sunda Islands. The Sunda Arc begins at Sumatra and ends at Flores, and is adjacent to the Banda Arc. The Sunda Arc is formed via the subduction of the Indo-Australian Plate beneath the Sunda and Burma plates at a velocity of 63–70 mm/year.
Trachyandesite is an extrusive igneous rock with a composition between trachyte and andesite. It has little or no free quartz, but is dominated by sodic plagioclase and alkali feldspar. It is formed from the cooling of lava enriched in alkali metals and with an intermediate content of silica.
Tres Vírgenes is a complex of volcanoes located in the Mulegé Municipality in the state of Baja California Sur, on the Baja California Peninsula in northwestern Mexico. This Volcano is part of a volcanic ridge that extends from Baja California towards the Guaymas Basin.
A melt inclusion is a small parcel or "blobs" of melt(s) that is entrapped by crystals growing in magma and eventually forming igneous rocks. In many respects it is analogous to a fluid inclusion within magmatic hydrothermal systems. Melt inclusions tend to be microscopic in size and can be analyzed for volatile contents that are used to interpret trapping pressures of the melt at depth.
The Samoa hotspot is a volcanic hotspot located in the south Pacific Ocean. The hotspot model describes a hot upwelling plume of magma through the Earth's crust as an explanation of how volcanic islands are formed. The hotspot idea came from J. Tuzo Wilson in 1963 based on the Hawaiian Islands volcanic chain.
The Macdonald hotspot is a volcanic hotspot in the southern Pacific Ocean. The hotspot was responsible for the formation of the Macdonald Seamount, and possibly the Austral-Cook Islands chain. It probably did not generate all of the volcanism in the Austral and Cook Islands as age data imply that several additional hotspots were needed to generate some volcanoes.
Ocean island basalt (OIB) is a volcanic rock, usually basaltic in composition, erupted in oceans away from tectonic plate boundaries. Although ocean island basaltic magma is mainly erupted as basalt lava, the basaltic magma is sometimes modified by igneous differentiation to produce a range of other volcanic rock types, for example, rhyolite in Iceland, and phonolite and trachyte at the intraplate volcano Fernando de Noronha. Unlike mid-ocean ridge basalts (MORBs), which erupt at spreading centers (divergent plate boundaries), and volcanic arc lavas, which erupt at subduction zones (convergent plate boundaries), ocean island basalts are the result of intraplate volcanism. However, some ocean island basalt locations coincide with plate boundaries like Iceland, which sits on top of a mid-ocean ridge, and Samoa, which is located near a subduction zone.
The Erebus hotspot is a volcanic hotspot responsible for the high volcanic activity on Ross Island in the western Ross Sea of Antarctica. Its current eruptive zone, Mount Erebus, has erupted continuously since its discovery in 1841. Magmas of the Erebus hotspot are similar to those erupted from hotspots at the active East African Rift in eastern Africa. Mount Bird at the northernmost end of Ross Island and Mount Terror at its eastern end are large basaltic shield volcanoes that have been potassium-argon dated 3.8–4.8 and 0.8–1.8 million years old.
The Dunedin Volcano is an extensively eroded multi-vent shield volcano that was active between 16 and 10 million years ago. It originally extended from the modern city of Dunedin, New Zealand to Aramoana about 25 km away. Extensive erosion has occurred over the last 10 million years and Otago Harbour now fills the oldest parts of the volcano. The remnants of the volcano form the hills around Otago Harbour.
Terry Ann Plank is an American geochemist, volcanologist and professor of earth science at Columbia College, Columbia University, and the Lamont Doherty Earth Observatory. She is a 2012 MacArthur Fellow and member of the National Academy of Sciences. Her most prominent work involves the crystal chemistry of lava minerals in order to determine magma ages and movement, giving clues to how quickly magma can surface as lava in volcanoes. Most notably, Plank is known for her work establishing a stronger link between the subduction of ocean sediments and volcanism at ocean arcs. Her current work can be seen at her website.
Plank states that her interest in volcanoes began when her Dartmouth professor took her and other students to Arenal volcano in Costa Rica. He had them sit and have lunch while on top of a slow-moving lava flow and while watching bright red goops of lava crack out from their black casings. "It was totally cool, how could you not like that?" Plank recalled the event to State of the Planet, an Earth Institute News source at Columbia University.
Hadean zircon is the oldest-surviving crustal material from the Earth's earliest geological time period, the Hadean eon, about 4 billion years ago. Zircon is a mineral that is commonly used for radiometric dating because it is highly resistant to chemical changes and appears in the form of small crystals or grains in most igneous and metamorphic host rocks.
The Rarotonga hotspot is a volcanic hotspot in the southern Pacific Ocean. The hotspot is claimed to be responsible for the formation of Rarotonga and some volcanics of Aitutaki but an alternative explanation for these islands most recent volcanics has not been ruled out. Recently alternatives to hotspot activity have been offered for several other intra-plate volcanoes that may have been associated with the Rarotonga hotspot hypothesis.
North Arch volcanic field is an underwater volcanic field north of Oahu, Hawaii. It covers an area of about 25,000 square kilometres (9,700 sq mi) and consists of large expanses of alkali basalt, basanite and nephelinite that form extensive lava flows and volcanic cones. Some lava flows are longer than 100 kilometres (62 mi).
Stanley Robert Hart is an American geologist, geochemist, leading international expert on mantle isotope geochemistry, and pioneer of chemical geodynamics.
Mud volcanoes in the Mariana fore-arc are a hydrothermal geologic landform that erupt slurries of mud, water, and gas. There are at least 10 mud volcanoes in the Mariana fore-arc that are actively erupting, including the recently studied Conical, Yinazao, Fantagisna, Asut Tesoro, and South Chamorro serpentinite mud volcanoes. These mud volcanoes erupt a unique serpentinite mud composition that is related to the geologic setting in which they have formed. Serpentinite mud is the product of mantle metasomatism due to subduction zone metamorphism and slab dehydration. As a result, the serpentinite mud that erupts from these mud volcanoes often contains pieces of mantle peridotite material that has not fully altered during the serpentinization process. In addition to pieces of altered mantle material, pieces of subducted seamounts have also been found within the serpentinite muds. Serpentinite mud volcanoes in the Mariana fore-arc are often located above faults in the fore-arc crust. These faults act as conduits for the hydrated mantle material to ascend towards the surface. The Mariana mud volcanoes provide a direct window into the process of mantle hydration that leads to the production of arc magmas and volcanic eruptions.
Catherine Chauvel is a geochemist at the Institut de Physique du Globe de Paris known for her research on the impact of volcanic activity on the chemistry of the mantle, continental crust, and island arc geochemistry.
