Evidence of Ancient Lake in California's Eel River Emerges

Science Daily ^ | Nov. 14, 2011

[george76]

A catastrophic landslide 22,500 years ago dammed the upper reaches of northern California's Eel River, forming a 30-mile-long lake, which has since disappeared, and leaving a living legacy found today in the genes of the region's steelhead trout...about 60 miles southeast of Eureka.

The river today is 200 miles long, carved into the ground from high in the California Coast Ranges to its mouth in the Pacific Ocean in Humboldt County.

The evidence for the ancient landslide, which, scientists say, blocked the river with a 400-foot wall of loose rock and debris

...

"Perhaps of most interest, the presence of this landslide dam also provides an explanation for the results of previous research on the genetics of steelhead trout in the Eel River," Mackey said, referring to a 1999 study by U.S. Forest Service researchers J.L. Nielson and M.C. Fountain. In their study, published in the journal Ecology of Freshwater Fish, they found a striking relationship in two types of ocean-going steelhead in the river -- a genetic similarity not seen among summer-run and winter-run steelhead in other nearby rivers.

An interbreeding of the two fish, in a process known as genetic introgression, may have occurred among the fish brought together while the river was dammed, Mackey said. "The dam likely would have been impassable to the fish migrating upstream, meaning both ecotypes would have been forced to spawn and inadvertently breed downstream of the dam. This period of gene flow between the two types of steelhead can explain the genetic similarity observed today."

[allmost]

Pleasant distraction.

[george76]

Without the acquisition of LiDAR mapping, the lake’s existence may have never been discovered

[beebuster2000]

so much of what we think really is permanent is just chance natural occurence. i read that the san fran bay was formed when an ice dam at benicia broke and flooded the what is now the bay, and that the bay will be gone in 1,000 years. yet, so much time and effort is spent on “preserving the bay” like it was somehow meant to be some permanent thing.

[RoadGumby]

I think we need to restore that old lake, since it was obviously a ‘good thing’ to have for the fish. / sarc

[george76]

Many ancient ports ( Roman and others thousands of years ago ) have silted up and went away .

The Colorado River [ and other rivers , likely ] has had many dams ( thru landslides or volcanic intrusions ) and resulting lakes...which , over time, had the expected results ( went back to a river ).

[NELSON111]

Many ancient ports ( Roman and others thousands of years ago ) have silted up and went away .

Ephesus is a fine example. A metropolis in its day...and over the centuries the River Cayster gradually silted up the port. This brought disease...and the whole town moved from the marshes.

Men, especially liberal men (Gore) doesn't seem to get the fact that the natural world is always changing.

[Bernard Marx]

the bay will be gone in 1,000 years. yet, so much time and effort is spent on “preserving the bay” like it was somehow meant to be some permanent thing.

A kindred spirit! The Earth is constantly changing due to forces far beyond real human control. We are such arrogant, short-sighted little creatures! Any first-year geology student has a far better understanding of humanity's place on this globe than 99% of the people dwelling on its surface and at the mercy of its many moods. Stop Plate Tectonics!

[GOP Poet]

Cool. Mystery answered.

[tubebender]

Did I miss where it says which branch of the Eel? 60 miles SE of Eureka puts it in the Garberville area of one branch.

[george76]

I do not know.

[SunkenCiv]

GGG managers are SunkenCiv, StayAt HomeMother & Ernest_at_the_Beach	join list or digest view topics view or post blog bookmark post a topic subscribe
Thanks george76. To all -- please ping me to other topics which are appropriate for the GGG list.

[Steve Van Doorn]

"I think we need to restore that old lake, since it was obviously a ‘good thing’ to have for the fish. / sarc"

you say / Sarc but a socialist would love the idea.

[COBOL2Java]

[21twelve]

I was thinking the same thing. And at “only” 22,000 years ago one might make a case that it was an ancestral native American fishing ground that needs to be returned to the natives.

[Flycatcher]

Thanks for the ping, George.

And speaking of "lost" lakes, I've heard some scuttlebutt that the environmentalists want to remove the dams on two northern California lakes on the upper Klamath River. The lakes are Iron Gate Reservoir and Copco Reservoir.

It's just talk now. I'll be following this story too if it gets legs.

[george76]

The eco- communists want to do anything to destroy freedom.

Pulling down dams is just part of their UN Agenda 21