Narrator: This is Science Today. Small glaciers once existed near Los Angeles as recently as the present interglacial period, which began several thousand years ago. Lewis Owen, a professor of geology at the University of California, Riverside, says their discovery has implications for understanding climate changes.
Owen: What we're trying to do is to quantify rates of climate change essentially and we do that by looking at geologic record. By understanding the past we can try and predict what's happening in the future.
Narrator: Owen says that five years ago the best you could do was to guess the dates of glaciers, but today using a technology called 'cosmogenic radionuclide dating' things have changed. This technology can date moraines, which are the accumulated earth and stones created by glaciers.
Owen: Our work has really provided the first set of dates and timing of glaciation right at the southwestern part of North America and prior to that, we could only guess at the age of those moraines at that time and the age of the fluctuations of glaciers because we didn't have these numerical dating techniques.
Narrator: For Science Today, I'm Larissa Branin.