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CURRENTLY ERUPTING VOLCANOES
KLIUCHEVSKOI Kamchatka Peninsula, Russia 56.06°N, 160.64°E; summit elev. 4,835 m
Increased summit activity at Kliuchevskoi on 15 February led KVERT to raise the Concern Color Code from Yellow to Orange <http//www.avo.alaska.edu/avo4/updates/color_code.html>. Ash explosions and incandescence at the summit were observed. Strombolian explosions expelled bombs about 300 m above the crater. Based on video data and observations, gas-and-steam plumes with small amounts of ash rose to altitudes of 5.3 km (17,400 ft) a.s.l. and drifted SW. A thermal anomaly at the summit was seen on satellite imagery.
Geologic Summary. Kliuchevskoi is Kamchatka's highest and most active volcano. Since its origin about 7,000 years ago, the beautifully symmetrical, 4,835-m-high basaltic stratovolcano has produced frequent moderate-volume explosive and effusive eruptions without major periods of inactivity. More than 100 flank eruptions have occurred during the past 3,000 years, mostly on the NE and SE flanks of the conical volcano between 500 m and 3,600 m elevation. The morphology of its 700-m-wide summit crater has been frequently modified by historical eruptions, which have been recorded since the late-17th century. Historical eruptions have originated primarily from the summit crater, but have also included major explosive and effusive eruptions from flank craters.
KILAUEA Hawaii, USA 19.43°N, 155.29°W; summit elev. 1,222 m
During 14-20 February, lava from Kilauea continued to flow from lava deltas into the ocean at the East Lae'apuki, Kamokuna, and East Ka'ili'ili entries. Incandescence was intermittently visible from several breakouts on the pali and from several vents in Pu'u 'O'o's crater. On 15 February, breakout surface lava from the Campout flow produced seven lava falls over the seacliff behind the East Lae'apuki bench. Lava continued to flow over the seacliff in this area for the rest of the reporting period. Tremor at Kilauea's summit continued at low levels.
Geologic Summary. Kilauea, one of five coalescing volcanoes that comprise the island of Hawaii, is one of the world's most active volcanoes. Eruptions at Kilauea originate primarily from the summit caldera or along one of the lengthy E and SW rift zones that extend from the caldera to the sea. About 90% of the surface of Kilauea is formed by lava flows less than about 1,100 years old; 70% of the volcano's surface is younger than 600 years. The latest Kilauea eruption began in January 1983 along the E rift zone. This long-term ongoing eruption from Pu`u `O`o-Kupaianaha has produced lava flows that have traveled 11-12 km from the vents to the sea, paving broad areas on the S flank of Kilauea and adding new land beyond the former coastline.
SourceUS Geological Survey Hawaiian Volcano Observatory http//volcano.wr.usgs.gov/hvostatus.php
STROMBOLI Aeolian Islands, Italy 38.79°N, 15.21°E; summit elev. 926 m
Based on news reports, lava from Stromboli was observed flowing from two craters near the summit on 27 February. One lava flow traveled down the flanks more than 900 m and reached the sea. Several explosions per hour were audible.
Geologic Summary. Spectacular incandescent nighttime explosions at Stromboli volcano have long attracted visitors to the "Lighthouse of the Mediterranean." Stromboli, the NE-most of the Aeolian Islands, has lent its name to the frequent mild explosive activity that has characterized its eruptions throughout historical time. The small, 926-m-high island of Stromboli is the emergent summit of a volcano that grew in two main eruptive cycles, the last of which formed the western portion of the island. The active summit vents are located at the head of the Sciara del Fuoco, a horseshoe-shaped scarp formed as a result of slope failure that extends to below sea level and funnels pyroclastic ejecta and lava flows to the NW. Essentially continuous mild Strombolian explosions, sometimes accompanied by lava flows, have been recorded at Stromboli since Roman times.
TUNGURAHUA Ecuador 1.47°S, 78.44°W; summit elev. 5,023 m
Volcanic tremor and long-period earthquakes from Tungurahua began at approximately 2100 on 23 February. On 24 February at 0310, tremor amplitude increased. Incandescent material was ejected 800 m above the summit and fell on the flanks about 1 km below the summit. An eruption plume drifted NW and roaring noises were audible. Gravel and sand-sized ash reportedly fell at Pillate (8 km W) and San Juan (40 km WSW) and in places accumulated up to 3 mm thick. Deposits of ash 2 mm thick were reported from Bilbao (8 km W), Cotaló (8 km NW), Manzano (8 km SW), and Choglontus (W).
On 25 February, 12 moderate to large explosions occurred according to seismic interpretation. Based on satellite imagery, MWO, pilot reports, and the IG, the Washington VAAC reported that ash plumes rose to altitudes of 7.6-12.2 km (25,000-40,000 ft) a.s.l. during 24-25 February. Plumes drifted SW and NW.
On 26 February, a plume with no ash content rose to 6 km (19,700 ft) a.s.l. and drifted W. Later that day, two explosions produced ash plumes that 7 km (23,000 ft) a.s.l. and again drifted W. On 27 February, incandescent material was ejected above the summit and fell on the flanks about 500 m down the flanks. Noises produced by material rolling down the flanks and "cannon shots" were heard during 25-27 February.
Geologic Summary. The steep-sided Tungurahua stratovolcano towers more than 3 km above its northern base. It sits ~140 km S of Quito, Ecuador's capital city, and is one of Ecuador's most active volcanoes. Historical eruptions have been restricted to the summit crater. They have been accompanied by strong explosions and sometimes by pyroclastic flows and lava flows that reached populated areas at the volcano's base. The last major eruption took place from 1916 to 1918, although minor activity continued until 1925. The latest eruption began in October 1999 and prompted temporary evacuation of the town of Baños on the N side of the volcano.
RUAPEHU North Island, New Zealand 39.28°S, 175.57°E; summit elev. 2,779 m
According to news articles, a “moderate” lahar from Ruapehu's crater lake traveled E down the Whangaehu River valley on 18 March and reached the sea 140 km away after a soft rock-and-ash dam was breached. The section of dam that failed was about 40 m long and 7 m high. There were no reports of injuries or major damage to infrastructure and only some flooding to farmlands at the base of the volcano. The volume of water and debris was estimated at 1.3 million cubic meters. On 19 March, IGNS confirmed a 6-m drop in the crater lake level and reported an increase in seismicity following the lahar.
Geologic Summary. Ruapehu, one of New Zealand's most active volcanoes, is a complex stratovolcano constructed during at least four cone-building episodes. The 110 cu km volcanic massif is elongated in a NNE-SSW direction and is surrounded by another 100 cu km ring plain of volcaniclastic debris. A single historically active vent, Crater Lake, is located in the broad summit region, but at least five other vents on the summit and flanks have been active during the Holocene. Frequent mild-to-moderate explosive eruptions have occurred in historical time from the Crater Lake vent. Lahars produced by phreatic eruptions from the summit crater lake are a hazard to a ski area on the upper flanks and to river valleys below the volcano.
Sources: New Zealand GeoNet Project http://data.geonet.org.nz/geonews/sab/,