Department of Earth, Atmospheric and Planetary Sciences
The Department of Earth, Atmospheric and Planetary Sciences (EAPS) has broad intellectual horizons that encompass the solid Earth, its fluid envelopes, and its diverse neighbors throughout the solar system and beyond. The department seeks to understand the fundamental processes defining the origin, evolution, and current state of these systems and to use this understanding to predict future states. The department currently comprises 39 faculty, including two with primary appointments in civil and environmental engineering, 173 graduate and undergraduate students, and over 115 research staff, postdoctoral appointments, and visiting scholars. EAPS is notable for its emphasis on interdisciplinary problems.
Educational Activities
EAPS has vigorous graduate educational programs in geology and geochemistry, geophysics, atmospheres, oceans, climate, and planetary science. The EAPS graduate program currently focuses on the PhD degree, which is the goal of about 95 percent of our graduate students. In the coming academic year, 155 graduate students will be registered in the department, including EAPS students in the MIT/Woods Hole Oceanographic Institution (WHOI) Joint Program. Of these, 99 are US citizens and 56 are international students. Women constitute 42 percent of the graduate student population. Twenty-six PhD and 12 SM degrees were awarded during the past academic year.
This past year, EAPS graduate students have taken more responsibility for shaping their educational experiences outside of the classroom. They have implemented a program to address women's issues and a mentoring program that pairs an incoming graduate student with a continuing student in an effort to ease the transition to graduate school. In addition, EAPS has established a mediation program in which a small number of faculty and staff serve as an informal but confidential avenue for addressing student challenges. A biannual prize continues to be awarded to recognize and reward the efforts of outstanding EAPS graduate teaching assistants.
EAPS remains committed to creating a strong presence in the undergraduate program at MIT. The department presents the undergraduate student body with the following opportunities to become acquainted with the world from the perspective of the earth sciences:
During this past year, EAPS has enhanced the program for majors, adding an Environmental Science option to existing options of Geoscience, Physics of Atmospheres and Oceans, and Planetary Science and Astronomy. The new track, which will integrate science and policy, will meet the needs of students who wish to investigate environmental problems on large space or long time scales.
Terrascope, the newest alternative to the freshman core program, continues to develop. Course 1.016 Introduction to Earth System Engineering and Science (spring term) has joined its companion course, 12.000 Solving Complex Problems (fall term) for the first time this past year. During spring break, students conducted research in the Brazilian rain forest that was based on their projects in the previous semester.
Faculty
Professor Ed Boyle was made an Honorary Fellow of the European Union of Geosciences. Professor Mario Molina received the Heinz Award for the Environment, an honorary degree from Tufts University, and the Sigma Xi McGovern Award. He was inducted as a member of the El Colegio Nacional in Mexico and participated in the inauguration ceremony of an ecological reserve in Queretaro named in his honor. Professor Roger Summons has been awarded the Alfred Treibs Medal of the Geochemical Society. Professor Rob van der Hilst was named the Cecil and Ida professor of earth and planetary sciences. He received the VICI grant for innovation research from the Dutch Science Foundation. Professor Benjamin Weiss received Caltech's Miltonand Francis Clauser Doctoral Prize "awarded to the Ph.D. candidate whose research is judged to exhibit the greatest degree of originality as evidenced by its potential for opening up new avenues of human thought and endeavor as well as by the ingenuity with which it has been carried out."Professor Carl Wunsch was elected to the American Philosophical Society. Professor Maria Zuber received a scientific achievement award from the American Association of Aeronautics and Astronautics.
Over the past two years, several vigorous searches have led to eight new faculty appointments. Roger Summons, whose work in "molecular fossils" is widely recognized and lauded, has been appointed professor of geobiology. Julian Sachs, an accomplished young paleoclimatologist, has joined the faculty as the Doherty assistant professor. David Mohrig, who has made notable contributions to sedimentary geomorphology, was named assistant professor of geology. James Hansen, who is doing innovative research on optimal observing and forecasting, has joined us as assistant professor of atmospheric science. Most recently, Raffaele Ferrari, who is an expert in the dynamics of small-scale circulations in the ocean, was appointed assistant professor in physical oceanography. Stéphane Rondenay was named assistant professor of seismology, Sang-Heon Dan Shim was named assistant professor of experimental geophysics, and Benjamin Weiss was named assistant professor of planetary sciences.
The department continues to do pioneer work in new interdisciplinary areas. The Earth System Initiative was formed in 2002 to encourage and coordinate multidisciplinary research efforts in the earth sciences and engineering at MIT. The Earth Resources Laboratory is broadening its base to include a wider range of geophysical, geological, and environmental topics. The Center for Global Change Science (including the Climate Modeling Initiative) and the Program in Atmospheric, Oceans and Climate continue to foster cross-fertilization among all areas of the earth sciences that control the climate system. Research activities are gradually broadening so that geologists are now working with oceanographers and atmospheric scientists, and models of the climate system have been constructed both for the modern system and for times deep in the geological past. Department faculty members also continue to play leading roles in the MIT Joint Program on the Science and Policy of Global Change.
Current Research
Professor Richard Binzel has been selected as a team member for the New Horizons mission to Pluto, approved by NASA and scheduled for launch in 2006.
Professor Samuel Bowring's research group continues to study the origin and evolution of the continental lithopshere; rates of biological evolution using the fossil record and high-precision geochronology; and development of new techniques for high-precision geochronology. This year they demonstrated that the Cambrian explosion was preceded by an extinction event with a duration much less than 1 million years. This is similar to other periods of evolutionary innovation in Earth's history, which appear to have been preceded by a major extinction.
Professor Edward Boyle has established the variability of the essential trace nutrient iron in central North Pacific Ocean surface waters near Hawaii: Iron responds to large dust storms from eastern Asia during the springtime. He has also established that anthropogenic lead is decreasing in the upper 1,000 m throughout the North Atlantic Ocean (a response to the phasing out of leaded gasoline in North America and Europe).
 Oblique view of southeastern part of the Tibetan Plateau. Diverse topographic features are a key to understanding the formation of the plateau. Photo courtesy of C. Burchfiel. |
Professor Clark Burchfiel's current work focuses on the nature of intracontinental deformation within different types of tectonic environments, with the goal of demonstrating the changing nature of the tectonic settings and rheology of the crust with time.
Professor Jim Elliot and his colleagues have found that the pressure of Pluto's tenuous nitrogen atmosphere has increased by a factor of two since 1988 and that extinction by hazes or clouds pervades the atmosphere. The cause of the pressure increase could be seasonal or climatic changes on Pluto's surface.
Professor Brian Evans and coworkers are studying the rates and mechanisms by which permeability and other transport properties change under hydrothermal conditions in the Earth. One conclusion is that compactive instabilities are possible even when rocks are deforming at relatively high temperatures—perhaps even when they are partially molten.
Professor Raffaele Ferrari has initiated a broad-based study of mesoscale motions in the upper ocean. The study addresses how momentum, buoyancy, and energy are transferred from climatological scales to submeter scales.
Professor Frederick Frey and students have focused their research on the long-term evolution of volcanism related to hotspots within the Earth's mantle, commonly interpreted as mantle plumes.
Professor John Grotzinger will participate as member of the Mars Exploration Rover science team, funded by NASA. Two rovers, dedicated to exploring Mars' climate history and searching for signs of water and life, will land on the surface of Mars in January 2004.
Professor Tim Grove and his colleagues have developed a new mechanism for the creation of Earth's early continental crust by subduction zone melting. The combination of water released from the descending lithosphere and the hotter overlying mantle leads to higher levels of mantle melting.
Professor Jim Hansen is exploring the impact of model inadequacy and nonlinearity on state estimation, ensemble construction, and probabilistic forecasting. He is developing a laboratory analog of atmospheric/oceanic flow for both research and education purposes.
Professor Thomas Herring is using global positioning system and very long baseline interferometry data to develop geophysically based models of changes in the rotation of the Earth and Earth deformations on global and regional scales.
Professor Kip Hodges' group focuses its research on the evolution of orogenic systems, attacking the problem through a combination of field geology, geochronology, and tectonic geomorphology. He is studying the interactions among erosional and deformational processes in shaping the Himalayas, continental subduction, and the exhumation history of ultrahigh-pressure rocks.
Professor Richard Lindzen has developed a new method for objectively deriving rainfall and cumulus activity from geostationary satellite data and for using this data to more accurately determine important climate feedbacks. He has also published a new theory describing the interaction of synoptic-scale tropical disturbances with convection.
Professor John Marshall has continued his studies of the Antarctic Circumpolar Current (ACC) of the ocean, a system of great importance to the global climate. He has developed a theoretical framework based on the meteorologist's "residual mean," which is being applied to understand the processes that set the stratification and tracer transport of the ACC.
Professor David Mohrig's group is studying the processes in river, tidal, and submarine settings to illuminate general versus environmentally specific controls on self-channelization.
Professor Mario Molina and Dr. Luisa Molina conducted a highly successful field measurement campaign to monitor air quality in Mexico City; the campaign included involvement of world-class investigators from the US, Mexico, and Europe. In collaboration with Professor Lawrence Susskind, an eight-party negotiation simulation was developed by students to introduce Mexican policy makers and stakeholders to the negotiated dynamics involved in using integrated assessment to make air quality management decisions.
Professor Ronald Prinn and his collaborators have used 25 years of their global measurements of CH3CCl3 to show that levels of OH (the major sink for CH3CCl3 and most other air pollutants) have varied cyclically from 1978 to 2002, with minima around 1980 and 1998. These surprising variations are not explained by current theory but may involve El Niño.
Professor Paola Malanotte-Rizzoli has continued to work on transport and heat exchanges between the subtropical and the tropical Atlantic Ocean and how they affect the global thermohaline circulation and development of ensemble data assimilation approaches to improve the predictability of ocean circulation models.
Professor Daniel Rothman has shown how dynamical features of the ancient carbon cycle may be determined from the carbon isotopic record. The work shows that the period of Earth's history preceding the evolution of complex animal life was characterized by a carbon cycle evolving far from a steady state.
Professor Julian Sachs is discovering episodes of abrupt climate change in the recent geological past. A new effort is aimed at using the hydrogen isotopic ratio of algal lipids preserved in ocean and lake sediments to evaluate past changes in the balance between precipitation and evaporation.
Professor Peter Stone and his collaborators have investigated how heat is taken up by the oceans in global warming experiments. They find that most of the heat is absorbed in the high latitudes of the North Atlantic and of the Southern Ocean, in part because that is where changes in the surface heat flux are strongest and in part because vertical mixing in the oceans is particularly sensitive to changes in the forcing in those locations.
Professor Roger Summons' new mass spectrometry equipment has been installed and is now operational in his geobiology laboratory. The first data set obtained is being used to evaluate a complex microbial ecosystem recorded in 2.7 billion-year-old sediments from the Pilbara region of Western Australia.
Professor Nafi Toksöz's research activities, under major cooperative projects, include obtaining a large volume of seismic data from China and from the eastern Mediterranean. These data are being analyzed to determine detailed structural and tectonic models in these regions.
Professor Rob van der Hilst and colleagues finished their comprehensive study of the seismological structure and mechanical strength of the Australian lithosphere, showing that seismic wavespeeds and discontinuity topography are consistent with a simple olivine-dominated mineralogy for the upper mantle. Preliminary results of a careful waveform analysis cannot be explained by variations in temperatures alone and demonstrate the need for variations in bulk composition in the deep mantle beneath the North Pacific.
Professor Kelin Whipple has been working on relationships between climate, erosion, and mountain range evolution. New data in the Nepal Himalayas strongly suggest climate-controlled patterns of deformation within the orogen. New theoretical developments demonstrate that rock uplift rate is more strongly influenced by climate-controlled erosional efficiency than by tectonic plate convergence velocity.
Professor Jack Wisdom has been investigating instances of anholonomy in classical mechanics and solar system dynamics. A body can change its orientation by a cyclic change in its shape, even without angular momentum. He realized this implies that deformable bodies can swim on curved manifolds.
Professor Carl Wunsch and colleagues are modeling global ocean circulation, both for the modern and previous climate states.
Professor Maria Zuber and colleagues combined altimetry data from their instrument on the Mars Global Surveyor spacecraft with high-energy neutron flux observations from the Mars Odyssey spacecraft to measure the ice content of the shallow subsurface of Mars. They found ice contents of between 50 and 70 percent by weight, which may possibly represent the frozen remnants of an ancient Martian ocean.
More information about the Department of Earth, Atmospheric and Planetary Sciences can be found on the web at http://www.eaps.mit.edu/.