Researchers have found the evidence of a lake that existed and got extinct during the Late Pleistocene, the Earth's latest Ice Age era, in California.
A research paper on the finding that has appeared online in the Nov. 14 edition of the journal Proceedings of the National Academy of Sciences reveals that the paleolake emerged from a massive landslide along California's Eel River.
A three-member research team, including Benjamin H. Mackey and Joshua J. Roering of the Department of Geological Sciences, University of Oregon in Eugene, and Michael P. Lamb of the Division of Geological and Planetary Sciences at California Institute of Technology, used remote sensing technologies to find the exact location of the lake as well as the evidence for landslide.
Combining analyses of 1-m resolution topographic data (acquired via airborne laser mapping) and field investigation, we present evidence for a large, landslide-dammed paleolake along the Eel River, CA, the authors-cum-researchers of the study has stated in their paper.
The landslide mass blocked the Eel River with an approximately 130-meter-tall dam that resulted in a 55-kilometers-long lake.
Evidence of the lake includes subtle shorelines cut into bounding terrain, deltas, and lacustrine sediments radiocarbon dated to 22.5 ka, they say.
According to researchers, although the effect of large landslide dams on river ecosystems and marine sedimentation is less apparent, the evidence of such a landslide lies in the genetic change in anadromous fish, which migrate to fresh waters for breeding, found in the river.
Researchers have explained that a striking genetic similarity was found in the summer-run and winter-run steelhead trout in Eel River, as compared to those found in other rivers, indicating they interbred, as the landslide dam would have blocked their migration route causing gene flow between the two reproductive ecotypes.