#hvo volcano watch

April is a month that carries deep layers of meaning on the Island of Hawaiʻi.

It was a dark and stormy night… and the volcano had a secret.

From Feb. 9-14, the US Geological Survey’s Hawaiian Volcano Observatory will welcome approximately 150 international volcanologists to Hilo to explore the impacts and insights of the 2018 Kīlauea eruption.

Olivine crystals—the beautiful green mineral common in Hawaiian lavas—record when and where magmas move inside Hawaiian volcanoes before they erupt. We can actually use these little crystals like clocks to better understand the magmatic events leading to the December 2020 and September 2021 summit eruptions at Kīlauea.

There were 2 events with 3 or more felt reports in the Hawaiian Islands during the past week: a M2.8 earthquake 21 km (13 mi)  WNW of Mountain View at 19 km (12 mi) depth on Aug. 25 at 9:25 a.m. HST and a M3.3 earthquake 9 km (5 mi) ENE of Pāhala at 32 km (19 mi) depth on Aug. 20 at 10:16 a.m. HST.

What are symptoms leading up to an eruption? The main player in monitoring volcanoes is seismicity—the frequency and magnitude of earthquakes.  When magma enters the volcanic edifice, it accumulates and makes space for itself by compressing many tiny void spaces.  Continued filling by magma creates pressure on the walls of reservoirs, causing slip, faults, or cracking in the surrounding brittle rock.  All these motions result in the generation of earthquakes. 

Closest to the US-Canada border, municipalities just south of Vancouver, British Columbia, sit on deposits from Mount Baker, located in Washington State. So, while the volcano itself is in the US, were it to erupt, the area near Vancouver could still be affected by hazards like mudflows and ash fall.

The collapse/explosion events generate plumes that have become progressively more ash-poor and now rise only a few thousand feet above the crater. This is in contrast to the eruptive sequence from May 16-26, when the vent within Halemaʻumaʻu crater was open.