Tuesday, November 20, 2012

GLOBAL VOLCANISM: The Volcano Discovery Report - Paluweh, Marapi, Popocatépetl, Fuego, Santiaguito, Concepcion, Masaya, Nevado del Ruiz, Reventador, Sakurajima, and Ruapehu!

November 20, 2012 - WORLDWIDE VOLCANOES - The following constitutes the new activity, unrest and ongoing report from the Volcano Discovery Group.


Ash explosions occur almost each day at Paluweh volcano (Rokatenda) off Flores, Indonesia. The activity seems to be increasing. The largest explosions have produced plumes rising up to 3 km altitude.

Marapi volcano on Sumatra (Indonesia) is showing signs of unrest or minor activity. A small steam (and possibly ash) puff was observed from the crater yesterday morning.

Popocatépetl volcano in Mexico has calmed down to only about 1-2 emissions per hour during the past days. Few of the explosions contained small amounts of ash. Glow remains visible at night.

Fuego volcano in Guatemala has picked up in activity again. Strombolian explosions have been gradually returning at the volcano: 5 were recorded between 18-19 and 13 during 19-20 Nov. They produced gray ash columns of 200-500 meters above the crater and dispersed up to 8 km towards south and southwest. The explosions ejected incandescent material to 100-150 meters above the crater and generated weak avalanches on the upper slope. The lava flow toward Ash Canyon is still active and had increased to 800 meters length this morning.

Santiaguito's activity remains at low levels and mainly effusive. There are only few and small explosions and the lava flows from the dome continue to be weakly active.

Pulses of volcanic tremor are regularly visible on the seismograms of Concepcion volcano in Nicaragua. In the past days, seismic activity seems to have been increased.

As Earthquake-report noted, tremor at Masaya volcano also in Nicaragua has been a bit higher recently with some few local earthquakes appearing on the seismic recordings.

A significant SO2 plume from Nevado del Ruiz volcano in Colombia is visible on the current NOAA satellite image. Seismic activity shows an increased number of small quakes and long-period events.

Reventador volcano in Ecuador continues to build up its lava dome and produce lava flows on the upper flanks. The latest report of the Instituto Geofisico warns of the possibility of increased explosive eruptions accompanied by pyroclastic flows that could affect a larger area.

After a phase of intense activity during 15-16 Nov, Sakurajima volcano has been more at average activity levels, with 1-2 daily explosions with ash plumes rising 7-8,000 ft (2.1-2.4 km) altitude.

Small earthquakes appear on the otherwise seismic recording from Ruapehu volcano in New Zealand. Alert level remains at 1 as an eruption is not thought imminent, but as a precaution, the New Zealand government has placed a safety exclusion zone of 2 km around the summit area. - Volcano Discovery.

No comments: