U.S. Earthquakes

  • M4.6 Earthquake Shakes Kīlauea Volcano, Widely Felt Across Hawaii

    At 11:20pm on Thursday, July 2nd (2020-07-03 09:20:01 UTC), a M4.6 earthquake shook the south flank of Kīlauea at a depth of about 4.2 miles.

    The estimated epicenter is within Hawaiʻi Volcanoes National Park beneath Pulama Pali, initially placed near the hairpin turn in the Chain of Craters Road.

    Reports have now come in from Maui, Lānaʻi, Oʻahu and Kauaʻi as well as shown on the map below.

    Those in the nearby Volcano communities report this as the heaviest shaking since 2018, perhaps due to proximity and shallower depth.

    Given its location and depth beneath the South Flank, this event falls into the post-2018 M6.9 grouping accommodating continuing flank movement.

    This does not on its own indicate any change in the non-eruption, but we will continue to monitor USGS feeds and reports for any changes warranting further public update.

    Two months ago, the USGS announced: We Don’t Want to be Alarmist, But we Also Need to Tell the Public That There Is an Increasing Possibility of Explosive Eruptions at Kilauea Volcano in Hawaii?

  • Major 7.8 Eathquake Strikes Alaska, Widespread Shaking Felt

    A powerful earthquake off Alaska’s southern coast jolted sparsely populated coastal communities late Tuesday…

    And some residents briefly fled to higher ground over fears of a tsunami.

    There were no immediate reports of damage in the Alaska Peninsula and the tsunami warning was canceled after the magnitude 7.8 quake offshore produced a wave of a less than a foot (30 centimeters).

    According to the U.S. Geological Survey, the earthquake struck Tuesday at 10:12 p.m. local time and was centered in waters 65 miles (105 kilometers) south-southeast of the tiny community of Perryville, at a depth of 17 miles (28 km).

    Because of the temblor’s location, some nearby Alaska Peninsula communities did not experience shaking that would normally be associated with the quake’s magnitude, said Michael West, Alaska state seismologist.

    Residents in some small towns within a hundred miles (160 kilometers) of the quake reported very strong shaking and some shaking was felt more than more than 500 miles (805 kilometers) away in the Anchorage area.

    The tsunami warning prompted coastal residents to evacuate to higher ground, with social media posts showing long lines of people fleeing towns like Homer and Kodiak as tsunami sirens wailed in the background.

    On Kodiak Island about 200 miles (320 kilometers) northeast of where the earthquake was centered, the local high school and the Catholic church opened their doors for evacuees and the school parking lot was declared a safe zone, with some people staying in their cars with pets until it was safe to go home.

    Officials at the National Tsunami Warning Center in Palmer, Alaska,began calling off the tsunami advisories and warnings after a wave of less than 1 foot (30 centimeters) was recorded in the community of Sand Point.

    I might have expected a little bit more water, but I’m happy that there wasn’t,” said David Hale, the senior duty scientist at the tsunami center.

    Now, watch the waves from the M7.8 Alaska earthquake roll across seismic stations in North America!

    Tuesday’s quake was more powerful than the magnitude 7.1 earthquake that caused damage in the Anchorage area in November 2018, although this earthquake released about 15 times as much energy as that earthquake.

    More than a dozen aftershocks of magnitude 4.0 or higher were reported immediately after the earthquake.

    We got people here who are going be working all night,” West said. ”These aftershocks will go and go and go and go.

    The earthquake happened in the so-called Alaska-Aleutian Trench, where a magnitude 9.2 quake in 1964 was centered.

    That remains the second most powerful earthquake ever recorded globally. The temblor and ensuing tsunami caused widespread damage and killed 131 people, some as far away as Oregon and California.

    Alaska is the most actively seismic U.S. state. Nearly 25,000 earthquakes have been recorded in Alaska since Jan. 1, according to the center. And it’s in the Ring of Fire!

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