Volcanos

Roundup of Global Volcanic Activity:

Stromboli (Eolian Islands, Italy): Magma levels inside the conduit of the NE vent remain very high, shown by frequent small overspills. Tremor is elevated and mixed with small to moderate explosion signals.

El Hierro (Canary Islands, Spain): A second, but weaker pulse of earthquakes combined with harmonic tremor started today. The quakes were located in the same area as the last quakes from the first swarm, i.e. at around 17 km depth just north of the western tip of the island below the El Golfo valley. At the moment, it seems that this pulse also is ending.

Tolbachik (Kamchatka): KVERT reports no significant changes, but apparently the tremor amplitude has risen again a bit (by about 20% compared to previous days). Lava flows continue to be fed from the active vent on the southern fissure. For the other volcanoes in Kamchatka, there is not much new is to report: Moderate seismicity accompanies ongoing lava extrusion and dome building at Sheveluch and Kizimen. Low seismic activity was reported from Karymski and Klyuchevskoi volcano remains currently calm at green level.

White Island (New Zealand): The strong tremor has suddenly dropped. A possible explanation might be that the conduit below the vent area has "dried out", with less water entering the system to produce the previous "loud" tremor and possible deep-seated phreatic explosions.

Kilauea (Hawai'i): Activity has remained essentially unchanged and stable. At the summit, the Halema'uma'u lava lake is very active, and rises and falls during alternating inflation and deflation cycles. On the east rift zone, activity continues from the Pu'u O'o vent where 4 hornitos are active from time to time (less than some weaks ago). Most lava is being diverted into lava tubes feeding two main flow fields: The most recent (Kahauale'a) is spreading from the northeast base of Pu'u O'o and currently covering the flows from 1983 to 1986 (i.e. the oldest of this eruption). Its most advanced lobe is 4 km from its source.

Popocatépetl (Central Mexico): Not much has changed overall. Emissions decreased again somewhat (about 2 per hour yesterday), and seismic activity has been weaker today as well.

Fuego (Guatemala): Activity has calmed down a bit again. INSIVUMEH reported 18 explosions (10 weak and 8 moderate) with ash plumes reaching 600-1200 m above the crater and drifting S and SE. The lava flow that emerged on 19 March had split into two lobes towards the Ceniza and Taniluya canyons and advanced to a total length of 1500 m. It was still weakly active this morning and had produced weak to moderate avalanches.

Telica (Nicaragua): The seismic swarm continues to increase in intensity. The earthquakes are still small (below magnitude 3), but some already show up on INETERS country-wide earthquake list, and are mostly located 5-10 km east of the volcano. No updates about unusual activity have been posted by INETER, so it is likely that this is (so far) only an intrusion at some depth with no significant surface activity.

Nevado del Ruiz (Colombia): An impressive SO2 plume was visible on the latest NOAA satellite image, suggesting that degassing activity has remained elevated.

Reventador (Ecuador): Strong steaming was observed during a window of clear weather. The seismic activity remains moderately high, with numerous moderate long period earthquakes, harmonic tremor pulses and signs of moderate explosions.

Tungurahua (Ecuador): Activity has remained relatively low. IG reported small explosions seen during the night 19-20 March and emissions of steam and minor ash amounts rising up to about 1 km.

Soufriere Hills (Montserrat, West Indies (UK)): MVO reported that during 8-15 March activity at the Soufrière Hills lava dome was at a low level. During a helicopter overflight on 8 March, scientists observed a large fissure in the cliff on the E side of the lava dome, part of which had existed since 2007. This fissure was the result of slow cooling and erosion of the dome. It was parallel to the cliff face and estimated to be 2 m wide, suggesting that a large slab was slowing moving away from the dome. The Hazard Level remained at 2 (on a scale of 1-5).