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 (The word "Sierra" means mountain range — annotated. Interpreter) for the last day.

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

Reports of the possible damage and no injuries were reported there. Among the above-mentioned earthquakes also included some of the earthquake in California on the border between the districts of Mono and Inyo (These counties are part of the piece. Calif. — annotated. Interpreter).

Translation: Anna Krasnov
Source: Los Angeles Times

Comment:

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

Here is a short description of California:
"California is earthquake-prone area, according to 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 are 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 (Fig. 1), the earthquake in Nevada do not occur along any of the previously known fault, it can mean several enhanced 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 of volcano: Caldera
The status of the volcano: the Pleistocene-Fumarolic
The last known eruption: Pleistocene
Elevation: 3,390 m (11,122 feet)
Latitude: Latitude: 37.70 ° N 37 ° 42'0 "N
Longitude: Longitude: 118.87 ° W 118 ° 52'0 "W

A large, 17 × 32 km, the valley of the caldera to the east of the central Sierra Nevada was formed by the eruption about 760,000 years ago. Most of the Long Valley eastern California is covered with rocks formed during volcanic eruptions in the last two million years. The catastrophic eruption 760,000 years ago formed the Long Valley caldera. This massive eruption was accompanied by hundreds of small eruptions over the next few thousand years. These eruptions — 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 by eruptions between 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.

Wide Long Valley caldera, which 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. The caldera was partially filled with pyroclastic flows during a catastrophic eruption, as well as many subsequent episodes of volcanic activity. The original topographic boundary walls of the caldera were increased as a result of landslides, glaciers, and rapid erosion. For example, geologists claim that the modern east wall of the caldera is 3-4 km further east than the original boundary. Caldera extends east from the flow of Glass Creek to Bald Mountain.

Source: Eye of the Planet

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