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Volcano Watch: Kilauea Update for March 22, 2012

(Activity update written by scientists at the U.S. Geological Survey’s Hawaiian Volcano Observatory.)

A lava lake present within the Halema’uma’u Overlook vent during the past week resulted in night-time glow that was visible from the Jaggar Museum overlook. The lake, which is normally about 90–115 m (295–377 ft) below the floor of Halema’uma’u Crater and visible by HVO`s Webcam, rose and fell slightly during the week in response to a series of large deflation-inflation cycles.

On Kilauea’s east rift zone, surface lava flows were active on the pali and upper coastal plain, in Royal Gardens subdivision, over the past week. As of Thursday, March 22, the flows were still more than 2 km (1.2 miles) from the coast, and there was no active ocean entry.

Two earthquakes beneath Hawai’i Island were reported felt this past week. A magnitude-2.7 earthquake occurred at 3:42 p.m., HST, on Monday, March 19, 2012, and was located 4 km (2 mi) southeast of Pu’ulena Crater at a depth of 2 km (1 mi). A magnitude-3.7 earthquake occurred at 00:04 a.m. (4 minutes after midnight) on Thursday, March 22, and was located 40 km (25 mi) west and offshore of Kailua-Kona at a depth of 33 km (21 miles).

…(Hawaii 24-7)

March 23, 2012 Posted by | Seismic, Volcanic | , , , , , , , | Leave a comment

Alert Raised at Galunggung Volcano in Indonesia

Lightning strikes during the 1982 eruption of Galunggung

The alert status of Galunggung volcano in West Java, Indonesia, was raised today (Mon 13 Feb 2012) due to an increase of its water temperature and a change in color.
Discoloration of the crater lake had started to be noticed in September 2011, but the changes have increased recently. According to the local volcanologists monitoring the volcano, the whole lake is now of muddy khaki color. In addition to the color change which could be caused by an increase of lake fumarole activity, an steep sudden increase by 13°C of the lake water temperature was detected, based on measurements taken on and before 5 February when it was at normal 27°C, and on 8 Feb, when it was 40°C warm.

Most fish in the lake have died and occasionally dead birds are found at the shore. No other signs of a possible volcanic awakening were detected at the moment. The ph level of the water is still at normal levels 7-8, and there is no sulfur smell. Also, no significant seismic activity has been detected. Nevertheless, PVMBG has now placed the volcano at alert level 2 (“watch”, on a scale of 1-4) and recommends to stay away at least 500 m from the lake shore.

The last eruptions of Galunggnug was a small phreatic explosion in 1984, and the major destructive eruption in 1982-83, which produced violent explosions with ash columns reaching 20 km height, pyroclastic flows and large lahars. The eruption destroyed an older lava lake, killed many people and displaced up to 35,000.

The eruption is infamous for the aircraft accident on 24 June 1982: a British Airways Boeing 747 with 262 people on board flew through the ash plume and had to make an emergency descent after the ash caused all 4 engines to fail; fortunately, the plane could land safely.

The present-day crater lake (Danau kawah Galunggung) has a diameter of 1000 m and is 11 m deep and contains a volume of about 8 million m3 of water. In the middle of the lake, a small 250 x 165 m diameter scoria cone which was produced during the final staged of the 1982-83 eruption rises to 30 m elevation.

A main hazard of the volcano are phreatic and phreatomagmatic eruptions capable of draining the lake and producing mud flows.

…(Volcano Discovery)

February 14, 2012 Posted by | Volcanic | , , , , , | Leave a comment