36 of Kuriles’ 68 Volcanic Centers Active Recently!

KURILE ISLAND VOLCANOES AND THE THREAT TO AVIATION

The remote Kurile Islands of the northwest Pacific stretch 1250 km (740 mi) from the tip of the Kamchatka Peninsula to northern Hokkaido, Japan. The Kuriles include 68 identified volcanic centers above sea level. Among them, 36 have been active in recent times and many are capable of producing sudden ash clouds that rise more than 15 km (50,000 ft) above sea level.

Some of the world’s most heavily traveled air corridors pass within a few hundred km of Kurile volcanoes. Daily, more than 200 aircraft and 25,000 people fly on these routes. Ash clouds can rise more than 1 km (3,300 ft) per minute, putting dozens of en route wide-body jets rapidly in harm’s way on a typical day in the North Pacific. Ash clouds travel with prevailing winds across hundreds or thousands of kilometers of airspace within a day. Inadvertent entry into an ash cloud can severely damage aircraft systems and, in the worst case, lead to complete engine failure. Ash fallout can also curtail ground operations at airports. (

(Excerpts and Image: KURILE VOLCANOES AND THE SAKHALIN VOLCANIC ERUPTION RESPONSE TEAM (SVERT)- AVO).

Related Links:

• Quick reference to the Active Volcanoes of the Kurile Islands: English (800 KB PDF)

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Lava Signs at Okmok Volcano

Okmok Activity – Color Code RED : Alert Level WARNING

Okmok Volcano Activity Notifications
by AVO

The eruption of Okmok Volcano continued throughout this week with persistent ash emissions rising from 15,000 to 25,000 feet. From July 19 to July 20 the color code was increased to red in response to a more vigorous eruptive episode which produced ash to 30,000 feet. Photographs and an overflight by Alaska Volcano Observatory staff on July 20 and 21 confirmed the existence of multiple vigorous vents on the caldera floor.

Photo of the Okmok eruption, July 24, 2008, taken from Ft Glenn on the east flank of Okmok Caldera. Picture Date: July 24, 2008. credit : Lonnie Kennedy – Source: AVO

Seismicity was characterized by intermittent bursts of volcanic tremor early in the week. This changed to continuous mid-level volcanic tremor on July 23, which persists to the current time. Amplitude of tremor has been generally constant since July 21.

Although there has been little change in the eruption in the past several days, stronger explosive activity could resume at any time with little or no warning.

AVO Weekly Update – 2008-07-25 12:18:38

The eruption of Okmok Volcano continued throughout this week with persistent ash emissions rising from 15,000 to 25,000 feet. From July 19 to July 20 the color code was increased to red in response to a more vigorous eruptive episode which produced ash to 30,000 feet. Photographs and an overflight by Alaska Volcano Observatory staff on July 20 and 21 confirmed the existence of multiple vigorous vents on the caldera floor.

Seismicity was characterized by intermittent bursts of volcanic tremor early in the week. This changed to continuous mid-level volcanic tremor on July 23, which persists to the current time. Amplitude of tremor has been generally constant since July 21.

Although there has been little change in the eruption in the past several days, stronger explosive activity could resume at any time with little or no warning.

Cleveland Activity – Color Code ORANGE : Alert Level WATCH

Cleveland Volcano Activity Notifications

2008-07-25 12:18:38 – Weekly Update by AVO
Based on reports from fishing boats Cleveland Volcano began erupting at approximately 12:00 AKDT (20:00 UTC) on July 21, 2008. This eruptive episode is more intense than that observed over the past several years. Pilot reports and satellite data have documented a persistent low level ash emission from 10,000 to 20,000 feet throughout the week when the volcano was visible through clouds. A large thermal anomaly suggests the presence of an ongoing active lava flow.

Related Links:

• Video by AVO/USGS geologist Tina Neal during an overflight of the eruption of Okmok Volcano and distant ash plume from Cleveland Volcano. July 21, 2008.
• Okmok Eruption, Cleveland Volcano [Update #2]
• Explosive Eruption at Okmok Volcano [Update #1]
• Volcanoes