USGS HVO Press Release—Magnitude-4.1 earthquake beneath Mauna Loa’s northwest flank, Island of Hawai‘i

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Magnitude-4.1 earthquake on Mauna Loa’s northwest flank, Island of Hawai‘i

The U.S. Geological Survey's Hawaiian Volcano Observatory (HVO) recorded a magnitude-4.1 earthquake located beneath Mauna Loa's northwest flank on Friday, December 4, at 7:44 a.m., HST. 

The earthquake was centered about 22 km (14 miles) east-northeast of Hōnaunau-Nāpōʻopoʻo, at approximately 5 km depth (3 miles). A map showing its location is posted on the HVO website at More details are available at the National Earthquake Information Center website at

Light shaking, with maximum Intensity of IV, has been reported across the Island of Hawai‘i. At that intensity, damage to buildings or structures is not expected.  The USGS "Did you feel it?" service ( received over 130 felt reports within the first hour of the earthquake.  

According to HVO acting Scientist-in-Charge David Phillips, the earthquake had no apparent effect on Kīlauea or Mauna Loa volcanoes. “We do not currently observe any changes in activity at Kīlauea or Mauna Loa as a result of this earthquake. Please be aware that aftershocks are possible and may be felt. HVO continues to monitor Kīlauea and other Hawaiian volcanoes for any changes.” 

Today's earthquake does not represent a significant departure from the seismic activity rate for the past year, so the Volcano Alert Level for Mauna Loa will remain at Advisory. Other Mauna Loa monitoring data streams show no significant change in deformation rates or patterns that would indicate increased volcanic hazard at this time. The earthquake this morning occurred in a location that has exhibited seismicity over the past several years. Earthquakes in this location, approximately 5 km (3 miles) northwest of Mauna Loa summit, are generally less than 8 km (5 miles) below the surface and smaller than magnitude-2.  

For information on recent earthquakes in Hawaii and eruption updates, visit the USGS Hawaiian Volcano Observatory website at