A series of small earthquakes recorded along the border between California and Nevada

Fig. 1

April 11. According to the U.S. Geological Survey, a lot of small earthquakes shook the border between the U.S. states of California and Nevada in the Eastern Sierra (By "Sierra" means mountain range — annotated. Translator) last day.

The strongest of them had a magnitude of 4.2 and 4.0, and both occurred on a Sunday afternoon in Hawthorne, pieces. Nevada, about 140 miles east of Sacramento. Weaker earthquakes continued Monday morning.

Reports of any damages or injuries were reported there. Some of the aforementioned earthquake also included some earthquakes in California on the border between Mono and Inyo counties (These counties are part of the piece. California — annotated. Translator).

Translation: Anna Krasnov
Source: Los Angeles Times

Comment:

Seismic activity for California is not news. USGS (U.S. Seismological Service) regularly fixes many small and sometimes large earthquakes.

Here is a short description of California:
"California is an earthquake-prone area, across the state there are many geological faults, the most famous of which — the San Andreas. Also in California, there are several volcanoes, including the dormant volcano Lassen Peak, which erupted in 1914 and 1921. "

Daily multiple concussions perceived norm. Fig. 2

So what was the media attention?

Eight earthquakes in Nevada as a sign of increased activity supervolcano in California

Fig. 3

 

As can be seen from the map (Figure 1), the earthquake in Nevada do not occur along any of the previously known fault, it can mean a few increased seismic activity associated with the movement of magma in the Long Valley caldera. Valley of the volcano provides a comprehensive view on the radius of the caldera and places it within the current series of earthquakes Nevada (Fig. 3).

Help volcano

Country: United States
Region: California (USA)
Volcano number: 120314-A
Type the volcano caldera
The status of the volcano: the Pleistocene-Fumarolic
The last known eruption: Pleistocene
Altitude: 3390 m (11,122 feet)
Latitude: Latitude: 37.70 ° N 37 ° 42'0? N
Longitude: Longitude: 118.87 ° W 118 ° 52'0? W

Large, 17 × 32 km caldera valley east of the central Sierra Nevada was formed by the eruption about 760,000 years ago. Much of the area of Long Valley eastern California covered rock formed during volcanic eruptions in the last 2 million years. Catastrophic eruption 760,000 years ago formed the caldera of Long Valley. This massive eruption was accompanied by hundreds of small eruptions in the next few thousand years. These eruption — lava flows, domes, and pyroclastic flows were concentrated in the central and western part of the caldera (green and yellow areas).

Mammoth Mountain (Mammoth Mountain) were formed between the eruptions of about 200 000 and 50 000 years ago. Volcanic activity then moved north to Mono Lake area about 35,000 years ago, to "create a mono craters." The last eruption occurred in the area of "mono" and "Inyo" crater about 600 years ago, and «Negit» Island in Mono Lake about 250 years ago.

Long Valley caldera broad that we see today are much smaller and slightly larger in diameter than it was immediately after the formation of about 760 000 years ago. At the time, as was originally caldera 2-3 thousand meters deep, it is now the highest point of the caldera is only about one thousand meters. Caldera has been partially filled with pyroclastic flows during a catastrophic eruption, as well as many subsequent episodes of volcanic activity. Original topographic boundary of the caldera walls have been increased as a result of landslides, glaciers, and rapid erosion. For example, geologists claim that modern east wall of the caldera 3-4 km further east than the original border. Caldera extends east from the flow of Glass Creek to Bald Mountain.

Source: Eye Planets

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