Nouvelles du volcan Kilauea
Kilauea volcano update: Continued summit subsidence evokes earthquake damage to Jaggar Museum and former HVO head quarters
Friday Jun 22, 2018 18:04 PM | IS
This image was captured during the helicopter overflight on June 18, 2018. It shows the growing Halema‘uma‘u crater viewed to the southeast, with HVO and Jagger Museum sitting on the caldera rim to give a better scale of the ongoing subsidence at the summit. (HVO/USGS)
This overflight image of Kīlauea's summit , taken on June 18, shows the continued dramatic slumping and collapse of the Halema‘uma‘u crater area. The photo shows the area north-northwest of Halema‘uma‘u near a GPS station, North Pit, that has subsided about 60 m (197 ft) in the past week alone. (HVO/USGS)
: A helicopter overflight on June 19 confirms that the Overlook parking area (closed since 2008) has largely slumped into the crater of Halema‘uma‘u. The image view is to the northwest and the road beneath the helicopter leads to the former parking area in the center right. (HVO/USGS)
Kilauea’s summit continues to steadily subside in response to the large volume of magma that was drained from beneath the caldera towards the lower East Rift Zone early May. This process is most pronounced around Halema’uma’u crater whose walls are falling in on itself and by now has grown to nearly twice its original width and depth – having partially swallowed the old overlook parking lot. What was once a 12-acre (0,05 square km) lava lake in the middle of the crater has grown to more than 130 acres (0.526 square km), at places up to 300 m (1000 ft) deep, and is getting larger every single day. A preliminary estimate of summit volume loss is around 260 million cubic meters as of June 15th, 2018.
The rock wall at the Jaggar Museum Overlook is cracked and crumbling. (HVO/USGS image taken June 18, 2018)
This slow but steady slumping of Halema’uma’u has given rise to a remarkable seismic pattern that has been established since the end of May and persists to this day. Over a time span of ca 20- 28 hour periods, lower seismicity (about 10 earthquakes an hour) quickly changes to more intense seismic activity (up to 35 earthquakes an hour) as pressure builds up deep inside the vent. Eventually this pressure built-up culminates in a gas driven explosion and seismic event larger than magnitude 5, creating a gas and ash plume that rises about 305 meter (1000 feet) before it quickly dissipates. These stronger events may thereby trigger partial collapses of the unstable rim of Halema’uma’u crater.
With around 500 earthquakes of magnitude 2 – 3 and higher on a daily basis, Kilauea’s summit is more or less constantly shaking and this seismicity is readily felt by the residents in nearby Volcano village. Meanwhile the dramatic changes that occur around Halema’uma’u are also affecting the nearby buildings of the Jaggar museum and HVO head quarters. Besides being covered with layers of ash and some smaller projectiles, these structures have suffered considerable earthquake damage.
Although they initially remained at the Hawaii Volcano Observatory after closure of Hawaii Volcanoes NP on May 4, 2018, the HVO scientists and staff eventually needed to evacuate the building and relocate to the University of Hilo by the end of May. Cracks have appeared in the walls and the flooring has buckled in response to the ongoing summit earthquakes and subsidence. Since closure of the park about 6 weeks ago, the Jaggar museum is all but deserted and the popular observation deck is now covered in ash, riddled with cracks and in general structurally unsound. Park staff have started to evacuate important exhibits and art work from the museum to store them elsewhere. It is not clear when the Jaggar Museum, founded in 1912, will re-open again to the public – if at all.
Below you can find the Facebook update of Hawaii Volcanoes NP on the damage in the Jaggar museum:
Thursday, Jun 21, 2018
Tuesday, Jun 19, 2018
Monday, Jun 18, 2018
Kilauea volcano update: Ongoing summit subsidence triggers continuous M2-M3 earthquakes with a daily M5 subsurface explosion
Monday, Jun 18, 2018
Kilauea’s summit caldera continues to subside in response to the withdrawal of magma from beneath the volcano’s summit that drains to the Lower East Rift Zone eruption site. The seismic cycle with M5 events and explosions in Halema’uama’u crater also persists, resulting in inward slumping of the crater rim and walls. ... [details]
Monday, Jun 18, 2018
Throughout the weekend, Kilauea’s lower East Rift Zone eruption persisted to vigorously effusive large amounts of lava from fissure 8 which travelled along the well established 13 km (8 mile) channel to the broad ocean entry at Kapoho. ... [details]