Monthly Archives: February 2009

How long does it take lava to cool?

Lava cools very quickly at first and forms a thin crust that insulates the interior of the lava flow. As a result, basaltic lava flows can form crusts that are thick enough to walk on in 10-15 minutes but the … Continue reading

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How does lava change its composition?

Geochemists use several elements to track the history of a batch of magma. For our example we’ll start with magnesium (and think of it as magnesium oxide, MgO, like the geochemists do). Beneath Hawaii, when the mantle melts it produces … Continue reading

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What is lava made of?

Lava is made up of crystals, volcanic glass, and bubbles(volcanic gases). As magma gets closer to the surface and cools, it begins to crystallize minerals like olivine and form bubbles of volcanic gases. When lava erupts it is made up … Continue reading

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Ubinas, Peru

INGEMMET reported that although cloud cover occasionally prevented visual observations of Ubinas, steam and steam-and-ash plumes were seen during 11-16 February and rose to altitudes of 5.7-6.5 km (18,700-21,300 ft) a.s.l. The plumes drifted NE, N, W, and SW. Source: … Continue reading

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Tungurahua, Ecuador

The IG reported that although visual observations of Tungurahua were occasionally limited due to cloud cover; gas-and-ash plumes were seen and rose to altitudes of 5.5-7.5 km (18,000-24,600 ft) a.s.l. during 11-17 February. Plumes drifted W, NE, E, and SE. … Continue reading

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Soufriére Hills, Montserrat, West Indies

MVO reported that during 6-13 February activity from the Soufrière Hills lava dome was at a low level. Two rockfalls were detected and seismicity was low. On 13 February, one small pyroclastic flow that originated in a gully on the … Continue reading

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Shiveluch, Russia

KVERT reported that seismic activity at Shiveluch was above background levels during 6-13 February. Based on interpretations of seismic data, ash plumes likely rose to altitudes of 5.5 km (18,000 ft) a.s.l. Lava flows continued to be active on the … Continue reading

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Shishaldin, Fox Islands

AVO reported that seismic activity from Shishaldin had returned to background levels in December 2008 and remained low. On 3 February, a weak thermal anomaly was detected on satellite imagery. The Aviation Color Code was lowered to Green and the … Continue reading

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Santa María, Guatemala

Based on analysis of satellite imagery, the Washington VAAC reported that on 12 February ash puffs from Santa María’s Santiaguito lava dome complex drifted WSW and W. On 16 and 17 February, INSIVUMEH reported that explosions produced ash plumes that … Continue reading

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Sakura-Jima, Japan

Based on analysis of satellite imagery and pilot observations, the Tokyo VAAC reported that during 11-12 February ash plumes from Sakura-jima rose to altitudes of 1.2-1.5 km (4,000-5,000 ft) a.s.l. Source: Tokyo Volcanic Ash Advisory Center (VAAC) – “Reports provided … Continue reading

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