New Computer Model Explains Lakes and Storms on Titan

PASADENA, Calif.—Saturn's largest moon, Titan, is an intriguing, alien world that's covered in a thick atmosphere with abundant methane. With an average surface temperature of a brisk -300 degrees Fahrenheit (about 90 kelvins) and a diameter just less than half of Earth's, Titan boasts methane clouds and fog, as well as rainstorms and plentiful lakes of liquid methane. It's the only place in the solar system, other than Earth, that has large bodies of liquid on its surface.

The origins of many of these features, however, remain puzzling to scientists. Now, researchers at the California Institute of Technology (Caltech) have developed a computer model of Titan's atmosphere and methane cycle that, for the first time, explains many of these phenomena in a relatively simple and coherent way.

In particular, the new model explains three baffling observations of Titan. One oddity was that Titan's methane lakes tend to cluster around its poles and that there are more lakes in the northern hemisphere than in the south.

Secondly, the areas at low latitudes, near Titan's equator, are known to be dry, lacking lakes and regular precipitation. But when the Huygens probe landed on Titan in 2005, it saw channels carved out by flowing liquid-possibly runoff from rain. And in 2009, Caltech researchers discovered raging storms that may have brought rain to this supposedly dry region.

Finally, scientists uncovered a third mystery when they noticed that clouds observed over the past decade—during summer in Titan's southern hemisphere—cluster around southern middle and high latitudes.

Scientists have proposed various ideas to explain these features, but their models either can't account for all of the observations, or do so by requiring exotic processes, such as cryogenic volcanoes that spew methane vapor to form clouds. The Caltech researchers say their new computer model, on the other hand, can explain all these observations-and does so using relatively straightforward and fundamental principles of atmospheric circulation.

"We have a unified explanation for many of the observed features," says Tapio Schneider, the Frank J. Gilloon Professor of Environmental Science and Engineering. "It doesn't require cryovolcanoes or anything esoteric." Schneider, along with Caltech graduate student Sonja Graves, former Caltech graduate student Emily Schaller (PhD '08), and Mike Brown, the Richard and Barbara Rosenberg Professor and professor of planetary astronomy, have published their findings in the January 5 issue of the journal Nature.

Schneider says the team's simulations were able to reproduce the distribution of clouds that's been observed-which was not the case with previous models. The new model also produces the right distribution of lakes. Methane tends to collect in lakes around the poles because the sunlight there is weaker on average, he explains. Energy from the sun normally evaporates liquid methane on the surface, but since there's generally less sunlight at the poles, it's easier for liquid methane there to accumulate into lakes.

But then why are there more lakes in the northern hemisphere? Schneider points out that Saturn's slightly elongated orbit means that Titan is farther from the sun when it's summer in the northern hemisphere. Kepler's second law says that a planet orbits more slowly the farther it is from the sun, which means that Titan spends more time at the far end of its elliptical orbit, when it's summer in the north. As a result, the northern summer is longer than the southern summer. And since summer is the rainy season in Titan's polar regions, the rainy season is longer in the north. Even though the summer rains in the southern hemisphere are more intense—triggered by stronger sunlight, since Titan is closer to the sun during southern summer—there's more rain over the course of a year in the north, filling more lakes.

In general, however, Titan's weather is bland, and the regions near the equator are particularly dull, the researchers say. Years can go by without a drop of rain, leaving the lower latitudes of Titan parched. It was a surprise, then, when the Huygens probe saw evidence of rain runoff in the terrain. That surprise only increased in 2009 when Schaller, Brown, Schneider, and then-postdoctoral scholar Henry Roe discovered storms in this same, supposedly rainless, area.

No one really understood how those storms arose, and previous models failed to generate anything more than a drizzle. But the new model was able to produce intense downpours during Titan's vernal and autumnal equinoxes—enough liquid to carve out the type of channels that Huygens found. With the model, the researchers can now explain the storms. "It rains very rarely at low latitudes," Schneider says. "But when it rains, it pours."

The new model differs from previous ones in that it's three-dimensional and simulates Titan's atmosphere for 135 Titan years—equivalent to 3,000 years on Earth—so that it reaches a steady state. The model also couples the atmosphere to a methane reservoir on the surface, simulating how methane is transported throughout the moon. 

The model successfully reproduces what scientists have already seen on Titan, but perhaps what's most exciting, Schneider says, is that it also can predict what scientists will see in the next few years. For instance, based on the simulations, the researchers predict that the changing seasons will cause the lake levels in the north to rise over the next 15 years. They also predict that clouds will form around the north pole in the next two years. Making testable predictions is "a rare and beautiful opportunity in the planetary sciences," Schneider says. "In a few years, we'll know how right or wrong they are.

"This is just the beginning," he adds. "We now have a tool to do new science with, and there's a lot we can do and will do."

The research described in the Nature paper, "Polar methane accumulation and rainstorms on Titan from simulations of the methane cycle," was supported by a NASA Earth and Space Science Fellowship and a David and Lucile Packard Fellowship.

Marcus Woo
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Ironing Out the Details of the Earth's Core

Caltech researchers obtain highest-pressure vibrational spectrum of iron

PASADENA, Calif.—Identifying the composition of the earth's core is key to understanding how our planet formed and the current behavior of its interior. While it has been known for many years that iron is the main element in the core, many questions have remained about just how iron behaves under the conditions found deep in the earth. Now, a team led by mineral-physics researchers at the California Institute of Technology (Caltech) has honed in on those behaviors by conducting extremely high-pressure experiments on the element.

"Pinpointing the properties of iron is the gold standard—or I guess 'iron standard'—for how the core behaves," says Jennifer Jackson, assistant professor of mineral physics at Caltech and coauthor of the study, which appears in the December 20 issue of Geophysical Research Letters. "That is where most discussions about the deep interior of the earth begin. The temperature distribution, the formation of the planet—it all goes back to the core."

To learn more about how iron behaves under the extreme conditions that exist in the earth's core, the team used diamond anvil cells (DAC) to compress tiny samples of the element. The DACs use two small diamonds to squeeze the iron, reproducing the types of pressures felt in the earth's core. These particular samples were pressurized to 171 Gigapascals, which is 1.7 million times the pressure we feel on the surface of the earth.

To complete the experiments, the team took the DACs to the Advanced Photon Source at Argonne National Laboratory in Illinois, where they were able to use powerful X-rays to measure the vibrational density of states of compressed iron. This information allows the researchers to determine how quickly sound waves move through iron and compare the results to seismic observations of the core. 

"The vibrational properties that we were able to measure at extraordinarily high pressures are unprecedented," says Jackson. "These pressures exist in the earth's outer core, and are very difficult to reproduce experimentally."

Caitlin Murphy, a graduate student in Jackson's group and first author of the paper, says the group was happy to find that their data set on the vibrational properties of iron evolved smoothly over a very wide pressure range, suggesting that their pressure-dependent analysis was robust, and that iron did not encounter any phase changes over this pressure range. To help achieve these successful measurements at high pressures, the group used some innovative techniques to keep the iron from thinning out in the DACs, such as preparing an insert to stabilize the sample chamber during compression. Additionally, they measured the volume of the compressed iron sample in situ and hydrostatically loaded the iron sample with neon into the sample chamber.

"These techniques allowed us to get the very high statistical quality we wanted in a reasonable amount of time, thus allowing us to obtain accurate vibrational properties of compressed iron, such as its Grüneisen parameter," says Jackson. "The Grüneisen parameter of a material describes how its total energy changes with compression and informs us on how iron may behave in the earth's core. It is an extremely difficult quantity to measure accurately."

The team was also able to get a closer estimate of the melting point of iron from their experiments—which they report to be around 5800 Kelvin at the boundary between the earth's solid inner core and liquid outer core. This information, combined with the other vibrational properties they found, gives the group important clues for estimating the amount of light elements, or impurities, in the core. By comparing the density of iron at the relevant pressure and temperature conditions with seismic observations of the core's density, they found that iron is 5.5 percent more dense than the solid inner core at this boundary.   

"With our new data on iron, we can discuss several aspects of the earth's core with more certainty and narrow down the amount of light elements that may be needed to help power the geodynamo—the process responsible for maintaining the earth's magnetic field, which originates in the core," says Jackson.

According to Murphy, the next step is to perform similar experiments alloying iron with nickel and various light elements to determine how the density and, in particular, the vibrational properties of pure iron are affected. In turn, they will be able to evaluate the amount of light elements that produce a closer match to seismic observations of the core.

"There are a few candidate light elements for the core that everyone is always talking about—sulfur, silicon, oxygen, carbon, and hydrogen, for instance," says Murphy. "Silicon and oxygen are a few of the more popular, but they have not been studied in this great of detail yet. So that's where we will begin to expand our study."

The study, "Grüneisen parameter of hcp-Fe to 171 GPa," was funded by the California Institute of Technology, the National Science Foundation, and the U.S. Department of Energy. Bin Chen, a former postdoctoral scholar in Jackson's lab, and Wolfgang Sturhahn, senior technologist at NASA's Jet Propulsion Laboratory and visiting associate at Caltech, were also coauthors on the paper. 

Katie Neith
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Moore Foundation Awards $6 Million for Research Leading to Earthquake Early Warning System

Released by the Gordon and Betty Moore Foundation:

PALO ALTO, Calif. —The Gordon and Betty Moore Foundation has awarded $6 million to three West Coast universities to create a prototype earthquake early warning system for the Pacific Coast of the United States.

The grant will allow seismologists at the University of California, Berkeley, California Institute of Technology (Caltech), and University of Washington, Seattle, in collaboration with the U.S. Geological Survey, to learn about the science of earthquakes and the best way to capture and analyze seismic data in order to give schools, utilities, industries and the general public as much time as possible—most likely seconds to several minutes—before the ground begins to shake.

"The Gordon and Betty Moore Foundation is funding this basic, fundamental science to yield an earthquake early warning prototype that we hope will pave the way for a fully functioning system in the Western U.S.,” said Cyndi Atherton, program director for science programs at the foundation. “A warning system has the potential to save thousands of lives and millions of dollars in the event of an earthquake, and we feel it is important to resolve any scientific questions that could stand in the way of implementing such a system.”

Each university will receive $2 million over three years.

“The technology and scientific expertise exist to create a sophisticated West Coast earthquake early warning system even more advanced than Japan’s now four-year-old system, which functioned well after the magnitude 9.0 Tohoku quake earlier this year,” said Richard Allen, director of the Berkeley Seismological Laboratory and a UC Berkeley professor of earth and planetary science. “We are gratified that the Foundation is supporting research that will help us bridge the gap between the current nascent test EEW system in California and a full West Coast ShakeAlert prototype.”

“The USGS has the federal responsibility to issue alerts for earthquakes, volcanoes, and landslides to enhance public safety and to reduce losses through effective forecasts and warnings. We look forward to integrating the expected results of the research funded by the Gordon and Betty Moore Foundation into our real-time earthquake monitoring systems,” said Doug Given, USGS seismologist, and EEW coordinator.

ShakeAlert, the current version of an early warning system now being tested by Caltech and UC Berkeley in collaboration with the Southern California Earthquake Center, ETH Zurich and the USGS, opens a pop-up alert on a recipient’s computer in the event of a major earthquake, listing quake location and magnitude and the estimated time before shaking should be felt. While people living near the epicenter of a quake will not have much warning, those farther from a large quake could have seconds or tens of seconds of notice before the ground shakes.

The universities will seek partners in industry to provide extra funding, test the prototype, and provide critical feedback about how they want to receive warning. and Deutsche Telekom's Silicon Valley Innovation Center have already partnered with the Berkeley Seismological Laboratory to financially support development of the prototype.

The grants from the Gordon and Betty Moore Foundation will help each university tailor its EEW system to the local fault system, addressing issues of rapid detection and prediction of shaking, and delivery of a warning to those in harm’s way.

“Our immediate goal in the Pacific Northwest is analysis of hundreds of GPS stations along with the existing seismometers to provide minutes of warning in the case of great coastal earthquakes,” said John Vidale, director of the Pacific Northwest Seismic Network and professor of earth and space sciences at the University of Washington, Seattle. “At first, the warnings will alert only a group of sophisticated industry and government partners while we iron out the wrinkles and build a case for a full-blown public system, as Japan already has.”

A comprehensive earthquake early warning system along the West Coast would cost approximately $150 million over five years. The California Integrated Seismic Network earlier this year estimated that a California system would cost about $80 million over 5 years, while a Pacific Northwest system would cost approximately $70 million. CISN is a partnership of universities, USGS, and the state of California, that monitors earthquakes throughout the state.

UC Berkeley will use some of its grant money to speed up processing of data from its network of GPS monitors, enabling real-time processing needed for rapid warnings. Caltech seismologists and engineers will work together to improve estimates of shaking as a function of distance from an earthquake's epicenter, and extend these estimates to how buildings will respond.

All three universities will utilize their regional seismic networks to improve accurate assessment of earthquakes as they occur, especially large earthquakes. Current EEW systems, for example, act as if quakes rupture at only one point, when in fact, in larger earthquakes, fault ruptures can extend over hundreds of kilometers.

“The Foundation’s grant is a huge contribution to moving forward the science of earthquake early warning systems,” said Thomas Heaton, director of the Earthquake Engineering Research Laboratory and professor of geophysics and of civil engineering at the California Institute of Technology.


USGS provides science for a changing world. Visit, follow us on Twitter @USGS and our other social media channels. Subscribe to USGS news releases via our RSS feed.

The Gordon and Betty Moore Foundation, established in 2000, seeks to advance environmental conservation and scientific research around the world and improve the quality of life in the San Francisco Bay Area. The Foundation’s Science Program aims to make a significant impact on the development of provocative, transformative scientific research, and increase knowledge in emerging fields. For more information, please visit

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Caltech Geophysicist Joann Stock Receives KINGDOM Educational Software Grant

Caltech Seismological Laboratory professor Joann Stock has been awarded a KINGDOM Software educational user license from Seismic Micro-Technology Inc. The $110,736.79, three-year license will significantly enhance geophysics and general geological computing resources in the lab. Stock and her group will use the software to interpret and visualize various data sets collected from ships using marine multichannel seismic reflection imaging to study the seafloor in locations near Antarctica, in the Gulf of California, and in the Indian Ocean. Problems they will study include activity on submarine faults and depositional patterns of nearshore sediments during periods of sea-level change.

The KINGDOM Software allows integrated geoscientific workflow spanning modeling, analytics, and data management for 3-D imaging of the faults and layers of sediment below Earth's surface. It provides a Windows-based geoscientific interpretation and allows Earth scientists to focus on analysis and interpretation of subsurface faults and layers.

For more information on Seismic Micro-Technology, click here.

Allison Benter
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Evidence of Ancient Lake in California's Eel River Emerges

Caltech-led team documents ecological changes that may explain the two different populations of once-related steelhead trout found today in the river

PASADENA, Calif.—A catastrophic landslide 22,500 years ago dammed the upper reaches of northern California's Eel River, forming a 30-mile-long lake—which has since disappeared—and leaving a living legacy found today in the genes of the region's steelhead trout, according to scientists at the California Institute of Technology (Caltech) and the University of Oregon.

Using remote-sensing technology known as airborne Light Detection and Ranging (LiDAR) and hand-held global positioning system (GPS) units, a three-member research team found evidence for a late Pleistocene, landslide-dammed lake–located about 60 miles southeast of Eureka, California—along the Eel River.

The river today is 200 miles long and carved into the ground from high in the California Coast Ranges to its mouth on the Pacific Ocean in Humboldt County.

The evidence for the ancient landslide—which, scientists say, blocked the river with a 400-foot wall of loose rock and debris—is detailed this week in a paper appearing online ahead of print in the Proceedings of the National Academy of Sciences. The study provides a rare glimpse into the geological and ecological history of this rapidly evolving mountainous region.

According to Benjamin H. Mackey, lead author of the study and a postdoctoral researcher at Caltech, the findings help to explain emerging evidence from other studies that show a dramatic decrease in the amount of sediment deposited from the river in the ocean just off shore at about the same time period.

Mackey and his colleagues were drawn to the Eel River, which is among the most-studied erosion systems in the world, to study large, slow-moving landslides. "While analyzing the elevation of terraces along the river, we discovered they clustered at a common elevation rather than decreasing in elevation downstream, paralleling the river profile, as would be expected for river terraces," he says. "This was the first sign of something unusual, and it clued us in to the possibility of an ancient lake."

By combining the findings from their field investigations with analysis of the topographic data provided by the LiDAR mapping, the team was able to identify a large landslide scar on the flank of a nearby peak, and detect subtle shorelines upstream of the landslide. The researchers suggest that a landslide in this area would have been capable of damming the river and creating a lake. An outcrop of finely laminated lake sediments discovered in a tributary stream provided compelling physical evidence for the lake’s existence.

An image constructed from high-resolution topography acquired via LiDAR remote sensing shows an oblique view of the reconstructed lake surface (transparent blue). The modern bed of the Eel River is the broad flat area across the center-left of the image. The inset shows sediment found upstream of the dam and indicate deposition in still water, typical of a lake environment. Charcoal within these sediments was radiocarbon dated to estimate the time of lake emplacement at 22,500 years ago.
Credit: California Institute of Technology

"Perhaps of most interest, the presence of this landslide dam also provides an explanation for the results of previous research on the genetics of steelhead trout in the Eel River," says Mackey, referring to a 1999 study by the U.S. Forest Service. In that study, researchers found a striking relationship between two types of ocean-going steelhead in the river—a genetic similarity not seen among summer-run and winter-run steelhead in other nearby rivers.

An interbreeding of the two fish, in a process known as genetic introgression, may have occurred among the fish brought together while the river was dammed, Mackey says. "The dam likely would have been impassable to the fish migrating upstream, meaning both ecotypes would have been forced to spawn and inadvertently interbreed downstream of the dam," he explains. "This period of gene flow between the two types of steelhead can explain the genetic similarity observed today."

Once the dam burst, the fish would have reoccupied their preferred spawning grounds and resumed different genetic trajectories, he adds.

"The damming of the river was a dramatic, punctuated affair that greatly altered the landscape," says coauthor Joshua J. Roering, an associate professor of geological sciences at the University of Oregon. "Although current physical evidence for the landslide dam and paleolake is subtle, its effects are recorded in the Pacific Ocean and persist in the genetic makeup of today's Eel River steelhead. It’s rare for scientists to be able to connect the dots between such diverse and widely felt phenomena."

The lake formed by the landslide, researchers theorize, covered about 12 square miles. After the dam was breached, the flow of water would have generated one of North America's largest landslide-dam outburst floods. Landslide activity and erosion have erased much of the evidence for the now-gone lake. Without the acquisition of LiDAR mapping, the lake's existence may have never been discovered, researchers say.

“This was a remarkable discovery, since large lakes in steep, rapidly uplifting mountain terrain are rare," says Michael P. Lamb, assistant professor of geology at Caltech and coauthor of the study. "Moreover, high erosion rates tend to erase evidence that past lakes ever existed. Ben was able to piece together subtle pieces of geologic evidence from landslides to shorelines to show that this lake existed, and that its presence is still felt thousands of years after its demise in local fish populations and in the marine sedimentary record."

The National Center for Airborne Laser Mapping provided the LiDAR data used in the project. Funding for the study, "Landslide-dammed paleolake perturbs marine sedimentation and drives genetic change in anadromous fish," was provided by the National Science Foundation and the Keck Institute for Space Studies at Caltech. 

Katie Neith

Wet and Mild: Caltech Researchers Take the Temperature of Mars's Past

PASADENA, Calif.—Researchers at the California Institute of Technology (Caltech) have directly determined the surface temperature of early Mars for the first time, providing evidence that's consistent with a warmer and wetter Martian past.

By analyzing carbonate minerals in a four-billion-year-old meteorite that originated near the surface of Mars, the scientists determined that the minerals formed at about 18 degrees Celsius (64 degrees Fahrenheit). "The thing that's really cool is that 18 degrees is not particularly cold nor particularly hot," says Woody Fischer, assistant professor of geobiology and coauthor of the paper, published online in the Proceedings of the National Academy of Sciences (PNAS) on October 3. "It's kind of a remarkable result."

Knowing the temperature of Mars is crucial to understanding the planet's history—its past climate and whether it once had liquid water. The Mars rovers and orbiting spacecraft have found ancient deltas, rivers, lakebeds, and mineral deposits, suggesting that water did indeed flow. Because Mars now has an average temperature of -63 degrees Celsius, the existence of liquid water in the past means that the climate was much warmer then. But what's been lacking is data that directly points to such a history. "There are all these ideas that have been developed about a warmer, wetter early Mars," Fischer says. "But there's precious little data that actually bears on it." That is, until now.

The finding is just one data point—but it's the first and only one to date. "It's proof that early in the history of Mars, at least one place on the planet was capable of keeping an Earthlike climate for at least a few hours to a few days," says John Eiler, the Robert P. Sharp Professor of Geology and professor of geochemistry, and a coauthor of the paper. The first author is Itay Halevy, a former postdoctoral scholar who's now at the Weizmann Institute of Science in Israel.

To make their measurement, the researchers analyzed one of the oldest known rocks in the world: ALH84001, a Martian meteorite discovered in 1984 in the Allan Hills of Antarctica. The meteorite likely started out tens of meters below the Martian surface and was blown off when another meteorite struck the area, blasting the piece of Mars toward Earth. The potato-shaped rock made headlines in 1996 when scientists discovered tiny globules in it that looked like fossilized bacteria. But the claim that it was extraterrestrial life didn't hold up upon closer scrutiny. The origin of the globules, which contain carbonate minerals, remained a mystery.

"It's been devilishly difficult to work out the process that generated the carbonate minerals in the first place," Eiler says. But there have been countless hypotheses, he adds, and they all depend on the temperature in which the carbonates formed. Some scientists say the minerals formed when carbonate-rich magma cooled and crystallized. Others have suggested that the carbonates grew from chemical reactions in hydrothermal processes. Another idea is that the carbonates precipitated out of saline solutions. The temperatures required for all these processes range from above 700 degrees Celsius in the first case to below freezing in the last. "All of these ideas have merit," Eiler says.

Finding the temperature through independent means would therefore help narrow down just how the carbonate might have been formed. The researchers turned to clumped-isotope thermometry, a technique developed by Eiler and his colleagues that has been used for a variety of applications, including measuring the body temperatures of dinosaurs and determining Earth's climate history.

In this case, the team measured concentrations of the rare isotopes oxygen-18 and carbon-13 contained in the carbonate samples. Carbonate is made out of carbon and oxygen, and as it forms, the two rare isotopes may bond to each other—clumping together, as Eiler calls it. The lower the temperature, the more the isotopes tend to clump. As a result, determining the amount of clumping allows for a direct measurement of temperature.

The temperature the researchers measured—18 ± 4 degrees Celsius—rules out many carbonate-formation hypotheses. "A lot of ideas that were out there are gone," Eiler says. For one, the mild temperature means that the carbonate must have formed in liquid water. "You can't grow carbonate minerals at 18 degrees other than from an aqueous solution," he explains. The new data also suggests a scenario in which the minerals formed from water that filled the tiny cracks and pores inside rock just below the surface. As the water evaporated, the rock outgassed carbon dioxide, and the solutes in the water became more concentrated. The minerals then combined with dissolved carbonate ions to produce carbonate minerals, which were left behind as the water continued to evaporate.

Could this wet and warm environment have been a habitat for life? Most likely not, the researchers say. These conditions wouldn't have existed long enough for life to grow or evolve—it would have taken only hours to days for the water to dry up. Still, these results are proof that an Earthlike environment once existed in at least one particular spot on Mars for a short time, the researchers say. What that implies for the global geology of Mars—whether this rock is representative of Martian history or is just an isolated artifact—is an open question.

The research described in the PNAS paper, "Carbonates in the Martian meteorite Allan Hills 84001 formed at 18 ± 4 °C in a near-surface aqueous environment," was supported by a Texaco Postdoctoral Fellowship, NASA, and the National Science Foundation.

Marcus Woo

Caltech Named World's Top University in New Times Higher Education Global Ranking

PASADENA, Calif.—The California Institute of Technology (Caltech) has been rated the world's number one university in the 2011–2012 Times Higher Education global ranking of the top 200 universities, displacing Harvard University from the top spot for the first time in the survey's eight-year history.

Caltech was number two in the 2010–2011 ranking; Harvard and Stanford University share the second spot in the 2011–2012 survey, while the University of Oxford and Princeton University round out the top five.

"It's gratifying to be recognized for the work we do here and the impact it has—both on our students and on the global community," says Caltech president Jean-Lou Chameau. "Today's announcement reinforces Caltech's legacy of innovation, and our unwavering dedication to giving our extraordinary people the environment and resources with which to pursue their best ideas. It's also truly gratifying to see three California schools—including my alma mater, Stanford—in the top ten."

Thirteen performance indicators representing research (worth 30% of a school's overall ranking score), teaching (30%), citations (30%), international outlook (which includes the total numbers of international students and faculty and the ratio of scholarly papers with international collaborators; 7.5%), and industry income (a measure of innovation; 2.5%) are included in the data. Among the measures included are a reputation survey of 17,500 academics; institutional, industry, and faculty research income; and an analysis of 50 million scholarly papers to determine the average number of citations per scholarly paper, a measure of research impact.

"We know that innovation is the driver of the global economy, and is especially important during times of economic volatility," says Kent Kresa, chairman of the Caltech Board of Trustees. "I am pleased that Caltech is being recognized for its leadership and impact; this just confirms what many of us have known for a long time about this extraordinary place."

"Caltech has been one of California's best-kept secrets for a long time," says Caltech trustee Narendra Gupta. "But I think the secret is out!"

Times Higher Education, which compiled the listing using data supplied by Thomson Reuters, reports that this year's methodology was refined to ensure that universities with particular strength in the arts, humanities, and social sciences are placed on a more equal footing with those with a specialty in science subjects. Caltech—described in a Times Higher Education press release as "much younger, smaller, and specialised" than Harvard—was nevertheless ranked the highest based on their metrics.

According to Phil Baty, editor of the Times Higher Education World University Rankings, "the differences at the top of the university rankings are miniscule, but Caltech just pips Harvard with marginally better scores for 'research—volume, income, and reputation,' research influence, and the income it attracts from industry. With differentials so slight, a simple factor plays a decisive role in determining rank order: money."

"Harvard reported funding increases similar in proportion to other institutions, whereas Caltech reported a steep rise (16%) in research funding and an increase in total institutional income," Baty says.

Data for the Times Higher Education's World University Rankings was provided by Thomson Reuters from its Global Institutional Profiles Project (, an ongoing, multistage process to collect and validate factual data about academic institutional performance across a variety of aspects and multiple disciplines.

For a full list of the world's top 200 schools and all of the performance indicators, go to

# # # 

The California Institute of Technology (Caltech) is a small, private university in Pasadena that conducts instruction and research in science and engineering, with a student body of about 900 undergraduates and 1,200 graduate students. Recognized for its outstanding faculty, including several Nobel laureates, and such renowned off-campus facilities as the Jet Propulsion Laboratory, the W. M. Keck Observatory, and the Palomar Observatory, Caltech is one of the world's preeminent research centers.

Kathy Svitil
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Caltech Geobiologist Receives Presidential Early Career Award

PASADENA, Calif.—Victoria Orphan, professor of geobiology at the California Institute of Technology (Caltech), is one of 94 winners of a Presidential Early Career Award for Scientists and Engineers (PECASE), the highest honor bestowed by the U.S. government on scientists and engineers beginning their independent careers.

Orphan, one of 13 Department of Energy (DOE) researchers in the 2011 class, was commended for "developing new techniques to study interactions between microbes, relevant for understanding the role of methane in the biosphere, which is of urgent importance for addressing the global carbon cycle and climate change; and for emerging leadership in the microbiology research community," according to the DOE.

"It is inspiring to see the innovative work being done by these scientists and engineers as they ramp up their careers—careers that I know will be not only personally rewarding but also invaluable to the nation," said President Obama in a statement issued September 26, announcing the awards.

The awards, established by President Clinton in 1996, are coordinated by the Office of Science and Technology Policy within the Executive Office of the President. Awardees are selected for their pursuit of innovative research at the frontiers of science and technology and their commitment to community service as demonstrated through scientific leadership, public education, or community outreach.

"I am deeply honored to have been selected as a PECASE awardee and grateful for the support by DOE's Biological and Environmental Research program," says Orphan, whose work spans the fields of environmental microbiology, ecology, and biogeochemistry, focusing primarily on the microbial cycling of methane. Her research—much of which is done using both manned and robotic submersibles to study areas of methane release in the deep sea—attempts to elucidate the metabolic links between microorganisms and their resulting impact on the cycling of carbon and nutrients in the environment.

Orphan received her PhD in biology in 2001 from UC Santa Barbara and was a National Research Council Postdoctoral Fellow at the NASA Ames Research Center before joining the Division of Geological and Planetary Science in 2004.

Kathy Svitil
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Out-of-this-world researchers join GPS faculty

Growing up on an army base on Kwajalein, a part of the Marshall Islands, Heather Knutson was dazzled at an early age by the starry night sky from her clear vantage point in the South Pacific. Her parents, however, convinced her that a career in astronomy was not very practical, so instead she explored physics and engineering as a teenager. Now, just seven years after receiving a bachelor's in physics from Johns Hopkins, Knutson is one of the most recent faculty recruits to Caltech's Division of Geological and Planetary Sciences. And as an assistant professor of planetary science, she's proving that space study can be practical after all.

"I spent two years during my undergrad studies working at the Space Telescope Science Institute, which, incidentally, is next to the physics building at Johns Hopkins," says Knutson. "It was there that I realized that it might actually be possible to pursue a career in astronomy. Obviously I'm not in an astronomy department now, but since the objects I study are planets, I guess you could call me a planetary astronomer. I never planned to end up where I did, but I'm very glad that I have."  

After earning her BS, Knutson went on to receive both a master's and doctoral degree in astronomy from Harvard. Prior to joining Caltech, she was a Miller Fellow at UC Berkeley for two years. Her research is focused on characterizing the properties of the planets that orbit stars other than our sun, including the temperatures, compositions, and atmospheric circulation patterns of these extra solar planets (or exoplanets)—all of which she tries to identify using observations of eclipsing systems.

"We have this giant, diverse, weird sample of planets—none of which match anything that we've seen before in our own solar system," says Knutson. "If we can learn something about the properties of these planets, then we can potentially learn a lot about planets in general—how they form, how they evolve, what's typical, what isn't, et cetera."

Exoplanets are too far away to be seen from Earth, and therefore are studied through measurements taken when the orbiting planet passes in front of or behind its parent star, which is visible. For example, as the planet passes in front of the star, it blocks part of the star's light in an event known as a transit. The amount of light the planet blocks indicates the radius of the planet relative to that of the star, she explains.

"I use telescopes to observe these objects and Caltech has wonderful resources," says Knutson, who also studies weather on exoplanets. "The great thing about being here is that there are not only top-notch telescopes that you can get time on, but there are actually telescopes that you can drive to."

Knutson isn't the only new faculty member in GPS who spends her time looking into space. Bethany Ehlmann, assistant professor of planetary sciences who joined Caltech in August following a Marie Curie Fellowship at the Institut d'Astrophysique Spatiale (Institute of Space & Astrophysics) in France, has her sights set on a planet that robots, and potentially humans, can actually visit: Mars.

"My primary skills are in remote sensing and analysis of satellite images, using data both from other planets and acquired around Earth. It's a skill set I like to deploy for a wide variety of problems," she says. "Most recently, I've been working on understanding environmental conditions early in Mars's history, via detection of minerals like clays, carbonates, and sulfates."

Ehlmann's interest in Mars and remote sensing began when she was an undergraduate at Washington University, where planetary scientist Ray Arvidson, who also runs an undergrad program in environmental studies, served as her mentor. During her time as a student and after graduating, she spent nine months at NASA's Jet Propulsion Laboratory, working science operations for the Mars Exploration Rovers.

"I was working on day-to-day mission operations immediately after they landed. After that experience, I was more or less hooked on planetary science," says Ehlmann, who went on to spend two years at the University of Oxford as a Rhodes Scholar and then earn a PhD as a National Science Foundation fellow in the Geological Sciences department at Brown University.

Back on the West Coast, her research focus at Caltech will be three-fold, Ehlmann says. She plans to continue looking into the early history of Mars and its changing environmental processes though time, and will also work to improve remote sensing techniques, particularly for remote compositional analysis, or remotely detecting the minerals that make up planetary surfaces. In addition, she hopes to add to the understanding of physical and chemical weathering processes on Earth and other planets.

"I was one of those students who, on college applications, would check ecology, astronomy, geology, environmental policy, international relations. What I like about space exploration is that it actually involves a little piece of each of those," she says. "And certainly the science I do on the Earth side has policy implications for understanding environmental change."

Ehlmann is also excited to be back at JPL, where her journey in space exploration began. She will have a joint appointment at the lab, which is managed by Caltech for NASA.

"Caltech is a great institution to be a part of, with excellent students and fellow faculty, as well as wonderful resources like JPL," she says. "I'll spend some of my time working on current missions, and perhaps with some of the scientists and engineers to develop instruments to propose for future opportunities in solar system exploration."

Katie Neith
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A Wave of New Earth-Science Faculty Joins GPS Division

Recent hires focus on ocean-related research

For Andrew Thompson, assistant professor of environmental science and engineering who joined the Caltech Division of Geological and Planetary Sciences in August, growing up in Rhode Island gave him a natural affinity for the ocean. However it wasn't until the summer before his senior year in college that he realized that he could put his fascination for the sea to good use.

"As a kid, I enjoyed math and physics, but thought oceanography was just about studying fish," says Thompson. While attending a summer program at Woods Hole Oceanographic Institution before his last undergrad year as an engineering student, however, he discovered that wasn't the case. "I learned there that I could do ocean science from a fluid-dynamics standpoint," he says, "and I fell in love with it."

After earning a BA in engineering sciences from Dartmouth, Thompson went on to receive an MPhil in fluid flow from the University of Cambridge and a PhD in physical oceanography from the Scripps Institution of Oceanography at UC San Diego. Thompson then returned to the UK for postdoctoral research stints at the University of East Anglia and the University of Cambridge. Before coming to Caltech, he spent a year as an advanced research fellow at the Natural Environment Research Council's British Antarctic Survey.

Throughout his studies, he never forgot the project at Woods Hole that first inspired him. 

"We looked at the transport of harmful algal blooms that had formed in the Gulf of Maine, which can be a serious economic and public-health problem," remembers Thompson. "The research I do now is actually very similar to that, but working in different regions of the ocean, primarily in the Southern Ocean around Antarctica."

Although Caltech doesn't have a long history of oceanography research, the Institute is striving to look very closely at climate from a holistic viewpoint at the Ronald and Maxine Linde Center for Global Environmental Science, where Thompson will have his lab among other scientists from a broad selection of disciplines. His physical ocean research focuses on eddies in the ocean, which are similar to atmospheric storms except that they happen in the water. They are important for mixing the ocean and transporting heat, chemicals, and biological elements. 

"I'm excited to be part of the Linde + Robinson Laboratory, which will bring people together from a wide range of backgrounds," says Thompson. "I think there will be a really good opportunity to broaden the work I've done and look at some of the implications on a larger scale."

While Thompson studies the way sea storms move things around, Victor Tsai, assistant professor of geophysics, is busy measuring the seismic noise produced by the movements of the ocean—partly from the crashing of waves onto the shore.

"My major focus right now is looking at sources of seismic energy other than earthquakes, and one of the biggest sources is ocean waves," he says. The waves create a noticeable seismic signal that can be recorded at seismic stations on the coast and inland. Analyzing this seismic noise helps researchers understand what makes up Earth's crust by tracking how fast the waves travel and how quickly they lose energy as they move through the earth.

Tsai also studies the effect that sea ice has on the seismic noise of ocean waves, which can give clues into how fast the ice is melting. His innovative research incorporates input from numerous fields, including seismology, geomechanics, glaciology, oceanography, and mathematical geophysics.

For Tsai, the new faculty appointment at Caltech is a bit of a homecoming. He earned a BS in geophysics here in 2004. Although he began his undergrad studies as a physics major, his first research project quickly showed Tsai that physics wasn't for him. He switched to geophysics, and his undergrad advisor was renowned seismologist Hiroo Kanamori, who influenced him to take a different look at the field.

"He had a research project for me that looked at atmospheric wave couplings with the solid earth," says Tsai. "That was my first geophysics project, and it was a bit unusual, since most people in the field aren’t looking at anything related to the atmosphere. I really enjoyed it, so I started to look for nontraditional geophysical problems to work on."

After Caltech, Tsai went on to earn an MA and PhD in Earth and planetary sciences at Harvard University. His postdoctoral work included a two-year Mendenhall Postdoctoral Fellowship at the Geological Hazards Science Center of the USGS in Colorado. In addition to seismic noise, Tsai, a member of Caltech's Seismo Lab, studies a wide variety of solid-earth topics, from the role of fluids in fault zones and understanding glacial earthquakes, to mechanical modeling of seismic events and improving current imaging techniques. He thinks the synergistic nature of the faculty here will help support and nourish his unique research interests.

"I really enjoy the way that people interact at Caltech," says Tsai. "Everyone shares ideas and are open to collaboration." 

Katie Neith