Gros Ventre Mountains magnitude 3.6 earthquake (3:43 AM, 24 February 2021) : 無料・フリー素材/写真
Gros Ventre Mountains magnitude 3.6 earthquake (3:43 AM, 24 February 2021) / James St. John
| ライセンス | クリエイティブ・コモンズ 表示 2.1 |
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| 説明 | The noise on this seismogram from the Snow King Mountain seismic station in Wyoming, USA represents shock waves from a magnitude 3.6 earthquake that hit in the Gros Ventre Mountains of northwestern Wyoming. According to the United States Geological Survey, the quake occurred at 3:43 AM, local time, on 24 February 2021, but this seismogram's signal starts before that. The epicenter was about 30 kilometers east-northeast of the town of Jackson (a.k.a. Jackson Hole), Wyoming. The hypocenter was about 7 kilometers deep.This earthquake occurred only 7 miles east-southeast of the famous Gros Ventre Landslide. In June 1925, a large rockslide occurred in the Gros Ventre River Valley, triggered by an earthquake that followed weeks of rain. Several cubic miles of debris blocked the river. A five mile long, ~200 feet deep lake formed behind the landslide dam. Two years later, the dam was breached by erosion and a considerable flood swept downstream - this destroyed the town of Kelly, resulting in six deaths. The Gros Ventre Landslide scar is still visible today.See info. at:earthquake.usgs.gov/earthquakes/eventpage/us6000dkmw/exec...anden.wikipedia.org/wiki/Gros_Ventre_landslide--------------------------------An earthquake is a natural shaking or vibrating of the Earth caused by sudden fault movement and a rapid release of energy. Earthquake activity is called "seismicity". The study of earthquakes is called "seismology". The actual underground location of an earthquake is the hypocenter, or focus. The site at the Earth's surface, directly above the hypocenter, is the epicenter. Minor earthquakes may occur before a major event - such small quakes are called foreshocks. Minor to major quakes after a major event are aftershocks.Most earthquakes occur at or near tectonic plate boundaries, such as subduction zones, mid-ocean ridges, collision zones, and transform plate boundaries. They also occur at hotspots - large subsurface mantle plumes (Examples: Hawaii, Yellowstone, Iceland, Afar).Earthquakes generate four types of shock waves: P-waves, S-waves, Love waves, and Rayleigh waves. P-waves and S-waves are body waves - they travel through solid rocks. Love waves and Rayleigh waves travel only at the surface - they are surface waves. P-waves are push-pull waves that travel quickly and cause little damage. S-waves are up-and-down waves (like flicking a rope) that travel slowly and cause significant damage. Love waves are side-to-side surface waves, like a slithering snake. Rayleigh waves are rotational surface waves, somewhat like ripples from tossing a pebble into a pond.Earthquakes are associated with many specific hazards, such as ground shaking, ground rupturing, subsidence (sinking), uplift (rising), tsunamis, landslides, fires, and liquefaction.Some famous major earthquakes in history include: Shensi, China in 1556; Lisbon, Portugal in 1755; New Madrid, Missouri in 1811-1812; San Francisco, California in 1906; Anchorage, Alaska in 1964; and Loma Prieta, California in 1989. |
| 撮影日 | 2021-02-24 12:07:55 |
| 撮影者 | James St. John |
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