Hawaii magnitude 4.8 earthquake (1:42 AM, 5 November 2024) 2 : 無料・フリー素材/写真
Hawaii magnitude 4.8 earthquake (1:42 AM, 5 November 2024) 2 / 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 | This seismogram is from the Hot Caves seismic station in Hawaii. The noise is from a magnitude 4.8 earthquake that hit the "Big Island" of Hawaii in the central Pacific Ocean. The quake occurred at 1:42 AM, local time, on 5 November 2024. The epicenter was about six kilometers southwest of the town of Pahala, Hawaii - this is southwest of Kilauea Volcano. The hypocenter was between 35 and 40 kilometers deep, which is well below the crust-mantle boundary in this area. Hawaii is probably the world's best example of a hotspot - an anomalous site of volcanic activity. Hotspots are large underground mantle plumes - magma rises through the mantle and crust and emerges at the surface to form volcanoes and volcanic complexes.--------------------------------Info. at:earthquake.usgs.gov/earthquakes/eventpage/hv74522742/exec...--------------------------------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 | 2024-11-05 10:38:48 |
| 撮影者 | James St. John |
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