Hawaiian Volcano Observatory

Volcano Watch

Volcano Watch is a weekly article and activity update written by U.S. Geological Survey Hawaiian Volcano Observatory scientists and colleagues.


Filter Total Items: 1,538
Date published: October 14, 2021

Volcano Watch — Large Earthquake reminds us to “Drop, Cover, and Hold On”

The magnitude-6.2 earthquake that occurred on Sunday, October 10 at 11:49 a.m. HST, originated just south of the Island of Hawai‘i. The large earthquake, caused by bending of the oceanic plate, serves as a stark reminder that the State of Hawaii is no stranger to potentially damaging earthquakes.

Date published: October 7, 2021

Volcano Watch — What’s that rising from the lava lake?

The past year has seen fluctuating lava lakes, ephemeral lava fountains, craggy spires, and drifting “islands” reminiscent of pre-1924 Halemaʻumaʻu activity at the summit of Kīlauea.  The recent activity has USGS Hawaiian Volcano Observatory (HVO) scientists reflecting on prior observations and how they compare to recent activity.  

Date published: September 30, 2021

Volcano Watch — A new eruption in Halemaʻumaʻu

Kīlauea volcano is erupting again. Wednesday afternoon, lava returned to Kīlauea's summit within Hawaiʻi Volcanoes National Park after a 4-month hiatus.  A new line of fissures sliced through the solidified crust of the 2020–21 lava lake in Halemaʻumaʻu at 3:21 p.m. HST.  

Date published: September 23, 2021

Volcano Watch — Observations and impacts of the 2017–2018 Ambae, Vanuatu eruption

The Pacific is home to dozens of active volcanic systems including the massive Hawaiian shield volcanoes Kīlauea and Mauna Loa. Most basaltic shield volcanoes in the Pacific are related to the hotspots that created the Hawaiian Islands and many of the Polynesian and Micronesian island chains.

Date published: September 16, 2021

Volcano Watch — How does HVO determine which regions are most threatened by lava flows?

Most residents of the Island of Hawaiʻi live on one of four potentially active volcanoes and probably have wondered about the threat of lava flows at one time or another. Interestingly, determining future threats relies on knowledge of the past. The long-term likelihood of an area being invaded by lava in the future, is estimated in two different ways based on the history of lava flow activity...

Date published: September 9, 2021

Volcano Watch — The MILEAGE project - Mapping Kīlauea’s Gas Emissions

Large quantities of volcanic gases, such as carbon dioxide (CO2), sulfur dioxide (SO2), and hydrogen sulfide (H2S), are released into the atmosphere during volcanic eruptions. But even between eruptions, smaller amounts of the same gases continue to escape and can provide important clues about the current state of the volcano and the underlying magma.

Date published: September 2, 2021

Volcano Watch — Eruption? Intrusion? What’s the difference?

We know that when a volcano erupts, molten red rock makes it to the surface, while during an intrusion it doesn’t. The difference between the two processes, if we depend on seismicity (earth shaking) or deformation (changes in ground surface) instrumentation, is not obvious. The events during the start of either are identical.  But we can’t be certain that an intrusion will lead to an eruption...

Date published: August 26, 2021

Volcano Watch — New Kīlauea Summit Intrusion Draws Comparison to Past Activity

Late Monday afternoon, earthquake activity picked up at Kīlauea’s summit.  At about 1:30 a.m. HST on Tuesday, that activity intensified, and it became clear that seismicity and increasing deformation were indicating a new intrusion of magma.  The seismicity extended southward from Hālemaʻumaʻu crater, to an area south of Kīlauea caldera.

Date published: August 19, 2021

Volcano Watch — ‘Ailā‘au—the largest subaerial Kīlauea lava flow

The 2018 lower East Rift Zone and 35-year-long Puʻuʻōʻō eruptions of Kīlauea had large impacts on the Puna District. Many residents were deeply affected by devastating lava flows, earthquakes, gas emissions, and other volcanic hazards. However, it is important to note that these eruptions are dwarfed compared to some past Kīlauea eruptions including the largest identified subaerial flow—‘Ailā‘...

Date published: August 12, 2021

Volcano Watch — 1790 was a bad year at Kīlauea

More people were probably killed by the 1790 eruption of Kīlauea than by any other eruption in what is now the United States. Several hundred men, women, and children perished during explosions at the summit of the volcano.  

Date published: August 5, 2021

Volcano Watch — A spaceborne sentinel keeps watch over Hawaiian volcanoes

Geologists at the USGS Hawaiian Volcano Observatory (HVO) had their mobile phones buzzing this past week with automated alert messages, notifying them that there was something new and hot on the Island of Hawaiʻi.  Although the internal alert system is meant to detect new volcanic activity, no eruption was occurring.  

Date published: July 29, 2021

Volcano Watch — Under the radar: Using weather stations to study Kīlauea’s December 20, 2020, plume

This week marks the second anniversary of the appearance of water in Kīlauea’s Halema‘uma‘u crater, so it seems timely to discuss the water lake’s demise last December 20, or rather, its transformation into a volcanic plume and how we use weather radar to investigate how that happened.