Carbon dating crude oil
Katherine Freeman, distinguished professor of geosciences at Penn State, uses it to follow crude oil compounds released from the 2010 Deepwater Horizon oil spill that were taken up by microbes living in sediments of the Gulf of Mexico.
More traditional uses of carbon dating also benefit from an AMS, because it provides more precise measurements of carbon-14 than other methods, and it can do so with incredibly tiny samples -- as small as 1 milligram.
It can take up to six months to have a sample tested.
The new Penn State lab, featuring a powerful Pelletron accelerator built by the Wisconsin-based National Electrostatics Corporation, should ease that crunch considerably.
It will enable precise dating of carbon-containing material with ages stretching back over the past 50,000 years." "This new facility will improve our ability to study human-environmental interactions where chronology is key," adds Kennett.
"It will be helpful in areas where we really need to know the order of events." For example, mammoths went extinct near the end of the last Ice Age, but whether the changing climate, disease, humans, or a comet impact did them in is a matter of debate that might be resolved with more precise dating techniques.
Archaeologists, environmental scientists, and other researchers produce thousands of potential AMS carbon-14 samples each year, but only two other high-precision AMS facilities exist in the United States, and access to them is limited.
Carbon dating has been used since the 1940s to determine the ages of archaeological finds.
Modern methods in mass spectrometry, far advanced since their development in the 1970s, now enable carbon dating to be applied to a wide range of new problems.
"Even though there are carbon-14 facilities around the world, science is still under-served," says Freeman.
"The new facility is an exciting addition both for Penn State and for the larger scientific community.