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Volcano Information Update # 2 for December 20th, 2020

The HIRSC - Weather Team received an update on the new eruption event at Halema'uma'u Crater that occurred on Sunday evening (December 20th).

Published by: HIRSC - Weather Team


Update # 2 as of 11:20 pm Sunday evening:

Shortly after approximately 9:30 p.m. HST, the USGS Hawaiian Volcano Observatory (HVO) detected glow within Halemaʻumaʻu crater at the summit of Kīlauea Volcano. An eruption has commenced within Kīlauea's summit caldera. The situation is rapidly evolving and HVO will issue another statement when more information is available.

Accordingly, HVO has elevated Kīlauea's volcano alert level to WARNING and its aviation color code to RED.

Alert levels and aviation color codes are explained here: https://www.usgs.gov/natural-hazards/volcano-hazards/about-alert-levels

HVO continues to monitor the volcano closely and will report any significant changes.

Stay informed about Kīlauea by following volcano updates and tracking current monitoring data on the HVO web page (https://www.usgs.gov/volcanoes/kilauea/volcano-updates) or by signing up to receive updates by email at this site: https://volcanoes.usgs.gov/vns2/.

HVO is in communication with Hawai'i Volcanoes National Park as this situation, which is taking place within the park, evolves.

HVO is in contact with the County of Hawai'i Civil Defense Agency.

Recent Observations:

For the past several weeks, the USGS Hawaiian Volcano Observatory (HVO) has recorded ground deformation and earthquake rates at Kīlauea Volcano's summit and upper East Rift Zone that have exceeded background levels observed since the conclusion of the 2018 lower East Rift Zone eruption and summit collapse.

Beginning in September 2020, increased rates of uplift were observed by GPS stations in Kīlauea's upper East Rift Zone. In the past month, increased uplift has also been measured at GPS stations in Kīlauea's summit region. While uplift related to post-collapse inflation of the summit reservoir has been occurring since March of 2019, rates have been steadily increasing in recent months and are currently higher than they have been since the end of the 2018 eruption.

In late November 2020, increased earthquake rates began when seismic stations recorded an average of at least 480 shallow, small-magnitude earthquakes (97% of which were less than or equal to magnitude-2) per week occurring at depths of less than 4 km (2.5 miles) beneath Kīlauea's summit and upper East Rift Zone. This compares to a rate of fewer than 180 per week following the end of Kīlauea's 2018 eruption and through early November 2020.

On December 2, 2020, GPS stations and tiltmeters recorded a ground deformation event at Kīlauea's summit. Accompanied by earthquake swarms, the patterns of ground deformation observed were consistent with a small dike intrusion of magma under the southern part of Kīlauea caldera. The injection resulted in about 8 cm (3 inches) of uplift of the caldera floor, and modeling suggests that it represented 0.4–0.7 million cubic meters (yards) of magma accumulated approximately 1.5 km (1 mile) beneath the surface. Though the intrusion did not reach the surface and erupt, it represented a notable excursion from trends observed in the Kīlauea summit monitoring data streams following the end of the 2018 eruption.

On December 17, 2020, seismometers detected a notable increase in occurrence and duration of long-period seismic signals beneath Kīlauea's summit, which are attributed to magmatic activity. Whereas this type of seismicity was observed on average once every few weeks following the 2018 eruption, rates have increased to over a dozen in the past several days.

Other monitoring data streams including volcanic gas and webcam imagery were stable until this eruption.

An earthquake swarm began on the evening of December 20, accompanied by ground deformation detected by tiltmeters. An orange glow was subsequently observed on IR monitoring cameras and visually beginning at approximately 21:36 HST.

From the Hawaii County Civil Defense (HCCD) at 11:15 pm Sunday evening:

This is a Civil Defense Message.

This is a Local Earthquake message for Sunday, December 20th.

The Hawaiian Volcano Observatory reports an eruption at the Halemaumau Crater of the Kilauea Volcano. Trade winds will push any embedded ash toward the Southwest. Fallout is likely in the Kau District in Wood Valley, Pahala, Naalehu, and Ocean View. Stay indoors to avoid exposure to ash.

As that activity was recorded the HIRSC Team has captured from the summit webcams, very visible orange and ash plume coming from the Halema'uma'u Crater. Contributors to HIRSC has confirmed a large orange glow coming from the Halema'uma'u Crater with ash plume billowing from the lake at the summit. Currently, a large crowd people are at the summit and witnessing the events unfolding.

The HIRSC Team has officially received official confirmation from the Hawaii Volcanoes National Park (HVNP) that a new eruption is occurring at the Halema'uma'u Crater via their Facebook page.

We will continue to monitor these events and several members of the HIRSC Team are en-route to Hawaii Volcanoes National Park to document some events.

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