Volcanos

Roundup of Global Volcanic Activity:

Stromboli (Eolian Islands, Italy): No lasting new larger lava flows have occurred over the past days, but it is obvious that the craters, in particular the NE vents, are literally "filled to the rim", and often produce small overflows from the crater. A strong tremor signal accompanies this process. Strombolian explosions in turn occur as well, but are comparably weak (in contrast to the elevated phase of activity in early Jan).

Etna (Sicily, Italy): A pronounced tremor spike showed up this morning, leading perhaps to the suspicion of a follow-up paroxysm (as Etna has sometimes done in the past). However, looking at webcam images from that time, it seems that an explosion and/or a collapse event (more likely) occurred from Voragine crater and produced a marked tremor spike. An ash plume and minor amounts of hot material can be seen rising a few 100 meters at around 04:51 local time. Typical for Etna's paroxysms, activity has ended quickly after reaching an impressive climax with lava fountains around and perhaps even above 1 km in height.

Marapi (Western Sumatra, Indonesia): A small explosive eruption occurred this morning at around 08:05 local time, generating a small ash plume rising a few hundred meters above the crater. Marapi volcano, one of Sumatra's most active, has been producing intermittent explosions with ash plumes up to 1 km high frequently since August 2011. For Indonesian standards, this is no big activity, and Indonesia's Volcanological Survey maintains alert level II only.

Popocatépetl (Central Mexico): Snow-covered Popo is taking a probably short rest with only 5 weak emissions of gas and steam and probably no ash having been observed during 24 hours since yesterday.

Santa María / Santiaguito (Guatemala): The rate of explosions seems to have increased,- INSIVUMEH mentions "abundant" small and moderate explosions with ash plumes rising up to about 1 km above the dome and drifting 13 km to the west. Effusive activity continues as well, with moderate near constant block avalanches from the several active flows on the dome's flanks.

Pacaya (Guatemala): The volcano continues to wake up. Small gas and ash emissions were observed from the crater yesterday. The seismic signal shows volcanic tremor and volcanic quakes related to internal fluid movements and the degassing/ash venting at the surface.

Fuego (Guatemala): Compared to the previous days, activity has a bit decreased. INSIVUMEH reports few weak to moderate explosions, and small glowing avalanches from the crater towards the Ceniza drainage visible at night. A new lava flow is predicted to re-appear in the coming days. The seismic signal showed relatively strong degassing tremor yesterday that decreased again. There are now discrete explosion signals mixed with some periods of weak volcanic tremor.

Telica (Nicaragua): An earthquake swarm has occurred last night at the volcano.

San Cristobal (Nicaragua): Banded volcanic tremor and some higher magnitude volcanic earthquakes have returned to show up on the seismic records.

Masaya (Nicaragua): A phase of increased tremor occurred yesterday. Today, it has eased again to normal levels.

Turrialba (Costa Rica): Increased degassing appears to have occurred yesterday. A weak SO2 plume is visible on yesterday's NOAA satellite image, and the seismic signal shows a phase of weakly increased tremor.

Nevado del Ruiz (Colombia): Seismic activity has been generally low. INGEOMINAS published some photos showing strong degassing from the volcano. The seismic recordings show small clusters of higher amplitude volcano-tectonic and volcanic earthquakes as well as continuous low-level tremor during the recent days.

Reventador (Ecuador): A thermal anomaly at the summit and continuing explosion earthquakes mixed with low-level volcanic tremor suggest that lava extrusion at the summit crater has resumed (or rather continues more vigorously) these days.

Tungurahua (Ecuador): The volcano alternates between strong activity with ash emissions and explosions and pauses. The corresponding seismic signal shows this with phases of frequent earthquakes and explosion signals merging into strong eruption tremor followed by rather quiet periods.