Pu’u ‘O’o Collapses 5-1-18

Pu’u ‘O’o Collapses as magma moves along the East Rift Zone:

Pu’u ‘O’o collapses amid swarms of shallow earthquakes indicating that magma may be moving to a new location along Kilauea’s East Rift Zone.

The Hawaiian Volcanoes Observatory (HVO) issued a new Volcanic Activity Notice this morning, detailing the rapidly evolving situation. Yesterday afternoon the floor of Pu’u ‘O’o Crater collapsed in two events between 2:00 pm and 4:00 pm. Swarms of small shallow earthquakes followed,moving eastward from the vent overnight concentrating in an area between Pu’u’ O’o and Hwy 130. An intrusion of magma occurred on the East Rift Zone and a new eruption along the East Rift Zone is one possible outcome, but it’s not possible to say where or when it may occur.

Hawai’i County Civil Defense issued an alert for residents of lower Puna this morning for the increased earthquake activity and potential for a new eruption. Parks and Recreation closed the Kalapana Lava Viewing Area as of this morning due to the potential dangers..

Starting mid-afternoon yesterday we noticed an increase in seismic tremor along Kilauea’s East Rift Zone as a cluster of small shallow earthquakes occurred near Pu’u ‘O’o Cone and the adjacent ERZ. We’re felt lots of quakes down at our Kalapana base yard causing the windows to rattle and the neighborhood dogs to bark furiously for a while after each large shaker. Many small earthquakes continued through the night with one magnitude 4 quake offshore about 2:30 am.

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Swarms of quakes overnight and this morning in orange and red. -Image: USGS-HVO

Even more exciting, about the same time the first earthquakes occurred, tiltmeters at Pu’u ‘O’o Cone recorded a major spike in inflation of 400 microradians and then an immediate rapid drop of 700 microradians! You can see by the relatively flat line from previous days that this huge change dwarfs the daily fluctuations of just a microradian or two. We didn’t know it at the time but this is what happened as the crater floor of Pu’u’O’o collapsed. 

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Tiltmeters recorded a major spike and drop yesterday afternoon. – Image : USGS-HVO

Pu’u ‘O’o Cone has recorded slow, but steady inflation for the past month indicating that magma has been accumulating at shallow depths near the cone. The floor of Pu’u ‘O’o Crater has also uplifted almost 25 feet over the past month and GPS recorded the cone itself has been expanding at an increasing rate. HVO issued recent Volcanic Activity Notices indicating that a new vent may soon form on or near Pu’u ‘O’o Cone.

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Kilauea’s Summit lava lake does not appear to be affected by the collapse. – Photo: NPS-Janice Wei

Kilauea’s summit has also been pressurized and last week the lava lake within Halema’uma’u rose so high that it overflowed multiple times, eventually flowing over about 75% of the crater floor. Spattering at the original lake margins built up an elevated edge. At the onset of deflation this weekend the lake surface again fell beneath the crater rim. As of this morning the summit eruption appears not to be affected by the Pu’u ‘O’o collapse or the East Rift Zone activity.

Rainy weather has blocked views from webcams near the cone so it’s hard to see any visible changes as of yet but as HVO scientist document last night’s events we’ll no doubt see some great images. This morning we’ve noticed a reddish plume up near Pu’u ‘O’o, which turns out to be fine ash particles from the collapse. An earlier attempt at reconnaissance by HVO geologists by helicopter was reportedly called off this morning due to this cloud of ash. You can see the still flying ash in this webcam view of the crater below.

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Flying ash is still visible in this webcam screen capture of Pu’u ‘O’o Crater: Image HVO North Rim Panorama webcam

What in the world will happen next? The suspense is killing us but it looks we’ll all just have to wait and see. Could this mean we’ll have lava back on the coastal plain and resume our lava tours again soon? Maybe, but there’s no way to say quite yet. These are very exciting times for sure so stay tuned!