Why do some earthquakes have negative depths?

Astute visitors to the U.S. Geological Survey Hawaiian Volcano Observatory (HVO) website may have noticed that some recent earthquakes have negative depths. This does not indicate a change in seismicity but, rather, an upgrade in HVO’s seismic data processing system.

January is Volcano Awareness Month on Hawaii

With the hustle and bustle of the holidays upon us, Hawaii Island residents are likely giving little thought to the volcanic terrain beneath their feet. And that’s all right — for now.

Drive along Saddle Road reveals outstanding volcanic geology

Route 200, the Daniel K. Inouye Highway, crosses Humuula Saddle, which separates Mauna Kea and Mauna Loa, the two largest volcanoes on Hawaii Island. This Saddle showcases outstanding volcanic geology and is easy to reach for “roadside geologists.”

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Magma: What’s hot and what’s not

Scientists at the U.S. Geological Survey’s Hawaiian Volcano Observatory routinely collect lava samples from Kilauea and use the chemistry of these samples to infer the temperature of magma (molten rock below Earth’s surface).

Magma: What’s hot and what’s not

Scientists at the U.S. Geological Survey’s Hawaiian Volcano Observatory routinely collect lava samples from Kilauea and use the chemistry of these samples to infer the temperature of magma (molten rock below Earth’s surface).

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Threat rankings of our nation’s geologically young volcanoes

Careful readers of the USGS Hawaiian Volcano Observatory website might have noticed mention of “threat rankings” in the lower right corner of our new home page (https://volcanoes.usgs.gov/observatories/hvo/). There, you’ll find a listing of Hawaii’s active volcanoes — Kilauea, Mauna Loa,