USGS HVO Press Release - Magnitude-4.2 Earthquake on the South Flank of Kīlauea Volcano

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A magnitude-4.2 earthquake beneath the south flank of Kīlauea Volcano was recorded by the U.S. Geological Survey's Hawaiian Volcano Observatory (HVO) on Tuesday, April 21, at 4:58 p.m. HST. 

The earthquake was located about 6.2 km (3.8 miles) south of Pu‘u ‘Ō‘ō and 44 km (27 miles) south of Hilo at a depth of 9.2 km (5.7 miles). This location is 10 km (6.2 miles) east of the magnitude-5.0 earthquake that occurred last week on Tuesday, April 14.

During the past 25 years, 16 earthquakes with magnitudes of 4 or greater and similar depths (8–12 km or 5–7 miles) have occurred in this area of Kīlauea's south flank. These quakes are thought to be caused by southward movement of the south flank in response to magmatic pressure within the east rift zone.

The U.S. Geological Survey received over 100 felt reports in the first 30 minutes after the earthquake (http://earthquake.usgs.gov/eqcenter/dyfi/) from people in northern and eastern regions of Hawai‘i Island.

The earthquake caused no apparent change to the current eruption of Kīlauea. Monitoring networks supported by HVO have not detected significant changes in volcano activity.

Daily updates about ongoing eruptions, recent images and videos of summit and East Rift Zone volcanic activity, maps, and data about recent earthquakes in Hawaii are posted on the HVO website at https://volcanoes.usgs.gov/observatories/hvo

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