By Becky Oskin
For the first time scientists can see how the shells of tiny marine organisms grow atom-by-atom, a new study reports. The advance provides new insights into the mechanisms of biomineralization and will improve our understanding of environmental change in Earth’s past.
Foraminifera are marine plankton with complex shells. The shells of dead forams in ocean sediments form a record of climate hundreds of millions of years into the past.
Led by researchers from the University of California, Davis and the University of Washington, with key support from the U.S. Department of Energy’s Pacific Northwest National Laboratory, the team examined an organic-mineral interface where the first calcium carbonate crystals start to appear in the shells of foraminifera, a type of plankton.
The National Science Foundation will award almost $5 million over five years to UC Davis to include the large earthquake-simulating centrifuge at the Center for Geotechnical Modeling as part of the new Natural Hazards Engineering Research Infrastructure program.
The geotechnical centrifuge at UC Davis is the largest of its kind in the world. It is used for scale model experiments on the effect of earthquakes on soils and buildings.
At the bottom of a frigid Antarctic lake, a thin layer of green slime is generating a little oasis of oxygen, a team including UC Davis researchers has found. It’s the first modern replica discovered of conditions on Earth two and a half billion years ago, before oxygen became common in the atmosphere. The discovery is reported in a paper in the journal Geology.
The switch from a planet with very little available oxygen to one with an atmosphere much like today’s was one of the major events in Earth’s history, and it was all because some bacteria evolved the ability to photosynthesize. By about 2.4 billion years ago, geochemical records show that oxygen was present all the way to the upper atmosphere, as ozone.
By Kat Kerlin
Recreating the violent conditions of Earth’s formation, scientists are learning more about how iron vaporizes and how this iron rain affected the formation of the Earth and Moon. The study is published March 2 in Nature Geoscience.
“We care about when iron vaporizes because it is critical to learning how Earth’s core grew,” said co-author Sarah Stewart, UC Davis professor of Earth and Planetary Sciences.
Shock and release
By Kat Kerlin
Researchers digging deeper into the origins of the Sutter’s Mill meteorite, which exploded over California’s Gold Country in 2012, have found diamonds and other “treasures” that provide important new insight into the early days of our solar system. They report their results in 13 papers in the November issue of Meteoritics & Planetary Science.
UC Davis scientists Akane Yamakawa and Qing-Zhu Yin in the Department of Earth and Planetary Sciences studied the different forms of the element chromium, called isotopes. They found that at least five different stellar sources composed of mixtures of 54-chromium-rich and -poor materials must have contributed matter to the nascent solar system four and half billion years ago. Some of these materials remained in the Sutter’s Mill meteorite.
About one-fifth of the Earth’s atmosphere is oxygen, pumped out by green plants as a result of photosynthesis and used by most living things on the planet to keep our metabolisms running. But before the first photosynthesizing organisms appeared about 2.4 billion years ago, the atmosphere likely contained mostly carbon dioxide, as is the case today on Mars and Venus.
Over the past 40 years, researchers have thought that there must have been a small amount of oxygen in the early atmosphere. Where did this abiotic (“non-life”) oxygen come from? Oxygen reacts quite aggressively with other compounds, so it would not persist for long without some continuous source.
Full post: Making oxygen before life
(454 words, 1 image, estimated 1:49 mins reading time)
A new pressure cell invented by UC Davis researchers makes it possible to simulate chemical reactions deep in the Earth’s crust. The cell allows researchers to perform nuclear magnetic resonance (NMR) measurements on as little as 10 microliters of liquid at pressures up to 20 kiloBar.
“NMR is our window into the chemical world,” said Brent Pautler, a postdoctoral researcher in chemistry at UC Davis and first author on the paper published July 2 in the online edition of the journal Angewandte Chemie. “It lets us see chemical reactions as they are happening.”
Full post: Reproducing deep-Earth chemistry
(440 words, estimated 1:46 mins reading time)
Completing this year’s science Nobels, the prize for chemistry goes to Martin Karplus, University of Strasbourg and Harvard University; Michael Levitt, Stanford University; and Arieh Warshel, University of Southern California, “for the development of multiscale models for complex chemical systems.”
The three scientists pioneered a method called molecular dynamics, where Newton’s Laws of motion are solved in time steps for an ensemble of many atoms, said William Casey, professor of chemistry at UC Davis.
“This method is now very wide spread and geochemists employ it a lot,” he said.
Full post: Chemistry Nobel for molecular dynamics
(347 words, 2 images, estimated 1:23 mins reading time)
Professor Howard Spero, chair of the Department of Geology, has received a Humboldt research award from the German government. Spero will use the award of 60,000 Euros (about $78,000) towards a sabbatical in Germany next academic year.
Spero studies changes in past climate and ocean circulation based on chemical traces in the fossil shells of tiny marine organisms called foraminifera, or “forams.” When they die, forams settle to the ocean bottom and accumulate in layers of sediment, creating a record of past ocean conditions.
The day before Super Bowl Sunday, take an afternoon for some super science museums. UC Davis’s second annual Biodiversity Museum Day will take place Saturday, February 2, from 1 to 4 pm. The event is a special opportunity to go behind-the-scenes to learn how research is conducted and to see some of the curators’ favorite pieces. Visitors are invited to spend time exploring displays, talking with scientists, and participating in fun activities and crafts.