A M5.0 earthquake hit 6km N of Johnson Lane, Nevada near Lake Tahoe.
Tremors have been felt up to Sacramento, reawakening fears of a quake-induced ancient tsunami that happened in the recent prehistoric past at Lake Tahoe.
The M5.0 earthquake, later downgraded to M4.5, hit Friday, March 20, 2020, 6:33 p.m, just east of Lake Tahoe in Nevada.
The major quake was followed by about two dozen ongoing small aftershocks.
Nearly 6,200 people reported feeling the earthquake on the USGS Homepage.
Reports came from South Lake Tahoe, Yerington and Fallon, as well as in the Sacramento Valley, Merced and Fresno.
Although not very strong, the shallow (5.2 miles deep) earthquake created loud earthquake booms, and people felt their whole homes shaking. Some said it was kind of scary. And some even started to fear a tsunami in Lake Tahoe.
Ancient tunami at Lake Tahoe
Lake Tahoe in California and Nevada is an example of a lake that is in danger of having a tsunami due to faulting processes.
Lake Tahoe has been formed by earthquakes and its bottom is criss-crossed by several faults… and others are hidden in glaciofluvial deposits.
Lake Tahoe has had many prehistoric eruptions. And with every earthquake, the lake gets deeper. Normally the lake deepens about 12 to 13 feet after each earthquake, but in one case, the lake bottom sediments moved by an amazing 32 feet (10 meters), even triggering a tsunami.
About 12,000 years ago, the western edge of lake Taho collapsed after a strong earthquake, triggering a gigantic underwater landslide. The resulting mega tsunami/seiche wave measured up to 330 ft (100 m).
And scientists say another strong earthquake will hit, it’s just a matter of when.
Tsunami and Seiche at Lake Tahoe
Tsunamis and seiches in Lake Tahoe are completely different than ocean tsunamis and seiches due to the ocean being deeper, and lakes being relatively shallow in comparison.
In contrast to ocean tsunami, where waves amplitudes only increase when the tsunami gets close to shore, lake tsunami waves are generated and stay in a shallow environment. So they are catastrophic!
A new mega tsunami at Lake tahoe would destroy and inundate some of the 34,000 permanent residences along Lake Tahoe. The resulting seiches would build up even larger standing waves due to the resonance phenomenon within the bay.
So yes, a new earthquake generated tsunami in Lake Tahoe would be devastating. And So if you live in the area, get ready for this deadly tsunami / Seiche scenario! More tsunami news on Strange Sounds and Steve Quayle. [Cosmic Tusk]