In a new paper in the journal Proceedings of the National Academy of Sciences, paleontologist Robert DePalma and his colleagues, including Walter Alvarez a Professor of the Graduate School and Professor Mark Richards from University of California, Berkeley Earth and Planetary Sciences, describe the site, dubbed Tanis, and the evidence connecting it with the asteroid or comet strike off Mexico’s Yucatan Peninsula 66 million years ago. That impact created a huge crater, called Chicxulub, in the ocean floor and sent vaporized rock and cubic miles of asteroid dust into the atmosphere. The cloud eventually enveloped Earth, setting the stage for Earth’s last mass extinction.
“It’s like a museum of the end of the Cretaceous in a layer a meter-and-a-half thick,” said Mark Richards, a UC Berkeley professor emeritus of earth and planetary science who is now provost and professor of earth and space sciences at the University of Washington.
Richards and Walter Alvarez, a UC Berkeley Professor of the Graduate School who 40 years ago first hypothesized that a comet or asteroid impact caused the mass extinction, were called in by DePalma and Dutch scientist Jan Smit to consult on the rain of glass beads and the tsunami-like waves that buried and preserved the fish. The beads, called tektites, formed in the atmosphere from rock melted by the impact.
Read the full article here
(Graphic courtesy of Robert DePalma)
Edwards Lab heads to sea to collect particulate lipid samples from the San Pedro Basin, halfway between Long Beach and Catalina Island. These samples will be used to study the microbial biology of the area and their impacts on ocean biogeochemistry. Learn more at the lab's website, https://www.bethanieedwardslab.com
Photos courtesy of Will Kumler, Edwards Lab Manager.
CIDER is a yearly interdisciplinary research incubator made possible by @BerkeleySeismo's Dr. Barbara Romanowicz, where Earth dynamicists collaborate on interdisciplinary new ideas like this:
Explore EPS summer classes! UC Berkeley is an open university during summer please review our schedule here.
This summer, you can gain an overview of the water supply that controls our natural ecosystems and human civilization in EPS 3 "The Water Planet."
Ever wonder what are our planets made of? Why do they orbit the sun the way they do? Why do some bizarre moons have oceans, volcanoes and ice? You can take a tour of the mysteries and inner workings of our solar system in EPS W12 "The Planets", an online course offering.
A very popular course, EPS 20 "Earthquakes in Your Backyard" gives students an introduction to seismology and geological tectonics, with particular emphasis on the situation in California.
EPS N82 "Introduction to Oceans" teaches students the geology, physics, chemistry and biology of the world oceans. The course will apply oceanographic sciences to human problems to explore topics such as energy from the sea, marine pollution, food from the sea, and climate change.
For information on these topics and other departmental course offerings, please click here.
UC Berkeley News uploaded a new video onto YouTube of Earth and Planetary Science Professor Jim Bishop explaining how he and his research team are utilizing robots to collect data on climate change.
Check out the USS Oceanus’ blog on the Lawrence Berkeley National Laboratory site: http://oceanbots.lbl.gov/.
Sarah Yang continues to update the research team's blog, so video interviews from scientists and crew will be posted on the site periodically. The scientists were very fortunate to have Sarah Yang to be at sea with them, as she was able to collect some cool videos and other materials. Remember, scientists were at sea for 10 days with ocean-going robots to measure carbon dioxide in the ocean and, hopefully, to unlock important data about climate change. For further access to Professor Jim Bishop and his team of researchers, go to the blog!
The EPS 118 Advanced Field Geology class is the capstone experience for geology majors in Earth and Planetary Science. The 2016 field camp took place at the Sierra Nevada Aquatic Research Laboratory (SNARL) in Mammoth Lakes, CA from June 3rd - July 1st. Students spend four weeks in the field integrating all of the training and knowledge gained in their geology coursework to address a large but focused question, and produce a map to answer scientific questions.
This video was taken by the EPS 118 students to show their camaraderie and experience in the field.
In fall 2016, Daniella Rempe joins the faculty of the University of Texas, Austin; she begins her tenure as an assistant professor in the Jackson School of Geosciences. Daniella is currently completing her graduate work with Professor William E. Dietrich in the UC Berkeley Department of Earth & Planetary Science.
Daniella specializes in hydrologic field observations, fluid flow and near surface geophysics. In layman's terms, she is obsessed with water; how it travels through rock; what it picks up along the way; and how water transforms the environment. She focuses on how landscapes store water in the shallow subsurface, a particularly relevant topic seeing how much of Earth's hilly regions are mantled with weathered rock. Daniella especially looks at the ecological significance of rock moisture; controls on the bottom boundary of the Critical Zone; and geophysical imaging of landscape scale patterns of weathering.
Daniella is proud to be a native Texan with the stupendous opportunity to take a teaching and research position at the flagship university. She was born in Houston, called Plano home for her secondary school years and then, obviously, lived in Austin for college. It must have been a case of serendipity for her to spend her undergraduate years in Central Texas, as Daniella credits her visits to Barton Springs as piquing her interest in water and hydrology. Barton Springs is a natural water-fed swimming hole playing host not only to sunbathers and swimmers but also to important geological processes such as faulting and the dissolution of limestone by infiltrating water. It was at Barton Springs that Daniella discovered her fascination and obsession with water.
Daniella will join the faculty of the Jackson School of Geosciences at UT as a hydrologist and geomorphologist.
For information on the Rempe Research Group, click here.
The work of Professor Barbara Romanowicz and recent graduate Dr. Scott French is highlighted on Berkeley News Center's page from earlier this month.
"University of California, Berkeley, seismologists have produced for the first time a sharp, three-dimensional scan of Earth's interior that conclusively connects plumes of hot rock rising through the mantle with surface hotspots that generate volcanic island chains like Hawaii, Samoa and Iceland."
Continue reading the full story on the Berkeley News website.
Applying a new waveform imaging methodology that takes advantage of accurate numerical seismic wavefield computations, Barbara Romanowicz's group has constructed a global shear velocity model in the upper mantle that reveals the presence of low velocity channels at the base of the oceanic asthenosphere. In a paper recently published in Science (http://www.sciencemag.org/content/342/6155/227), graduate student Scott French, former graduate student Vedran Lekic (now assistant professor at the University of Maryland) and Barbara Romanowicz show that these quasi-periodic finger-like structures of wavelength ~2000 km, stretch parallel to the direction of absolute plate motion for thousands of kilometers. Below 400 km depth, velocity structure is organized into fewer, undulating but vertically coherent, low-velocity plume-like features, which appear rooted in the lower mantle. This suggests the presence of a dynamic interplay between plate-driven flow in the low-velocity zone, and active influx of low-rigidity material from deep mantle sources deflected horizontally beneath the moving top boundary layer. Hotspots are not the direct consequence of plumes impinging on the lithosphere
Over the last three years, Burkhard Militzer's group has been working on understanding water at megabar pressures with ab initio computer simulations. In the interiors of Uranus and Neptune (dashed lines in figure) where such pressures exist, water is predicted to occur in a superionic state where the oxgyen atoms remain stationary like in a solid while the hydrogen atoms diffuse throughout the crystal like a fluid. In the most recent article that appeared in the journal Physical Review Letters, postdoc Hugh Wilson, summer student Michael Wong, and Burkhard Militzer, show that, at 1.0±0.5 megabars, the oxygen sub-lattice in superionic water changes from a body-centered cubic lattice to an face-cented cubic lattice (inset). This transformation lead to a more efficient packing but also reduces the diffusion rate of the hydrogen atoms, which may have further implications for electronic conductivity and magnetic dynamo in Uranus and Neptune. This theorectical prediction is expected to be verified with laboratory experiments using shock wave and x-ray diffration techniques.