In this photo provided by the Alaska Volcano Observatory/U.S. Geological Survey is the Tanaga Volcano near Adak, Alaska, on May 23, 2021. A swarm of earthquakes occurring over the past few weeks has intensified at a remote Alaska volcano dormant for over a century, a possible indication of an impending eruption. The Alaska Volcano Observatory raised the alert level to advisory status for Tanaga Volcano late Tuesday, March 7, 2023, after the quakes became very vigorous.
(Matt Loewen/Alaska Volcano Observatory/U.S. Geological Survey via AP)
MARK THIESSEN
Wed, March 8, 2023
ANCHORAGE, Alaska (AP) — A swarm of earthquakes occurring over the past few weeks has intensified at a remote Alaska volcano dormant for over a century, a possible indication of an impending eruption.
The Alaska Volcano Observatory raised the alert level to advisory status for Tanaga Volcano late Tuesday after the quakes became very vigorous.
“We started seeing a whole lot of earthquakes occurring, one after the other, several per minute,” said John Power, a research geophysicist with the U.S. Geological Survey stationed in Anchorage at the Alaska Volcano Observatory.
There have been hundreds of small earthquakes, none larger than magnitude 2.75, but they are concentrated beneath the summit of the volcano, he said.
“That indicates that we’re seeing significant unrest at the volcano,” Power said.
“Whether or not this will lead to an eruption is something we can’t say at this point in time,” he said. “But we are concerned about it enough that we have gone and elevated the warning level.”
While the increase causes concern, he said many times earthquake activity will drop off with no eruption.
“It’s anybody’s guess as to where this particular round of earthquake activity may end up,” he said.
The volcano is on an uninhabited island in the western Aleutians, about 1,250 miles (2,012 kilometers) southwest of Anchorage. There are no communities or structures there, but Adak, a city of about 170 residents on another island, is about 65 miles (105 kilometers) away and could see ashfall.
If the volcano were to erupt, the biggest threat would be to aircraft. The Aleutians are below the routes that jets fly between North America and Asia. Volcanic ash is angular and sharp and can cause an airplane engine to shut down. Previous eruptions had both ash clouds and viscous lava that moves very slowly away from the mountain, much like what happened at Mount St. Helens in Washington state in 1980.
“It’s very different than what you would see, for example, in Hawaii, Kilauea or Mauna Loa, where you see these beautiful red rivers of lava flowing down the side of the volcano," Power said.
Tanaga is actually part of a three-volcano complex on the island. It’s the tallest of the three at 5,925 feet (1,806 meters). It sits in the middle, with Sajaka, a 4,443-foot volcano to its west. Sajaka had an older cone that collapsed into the North Pacific Ocean with a new cone that has emerged.
To the east of Tanaga is Takawangha, a 4,75-foot (1,449-meter) volcano that is mostly ice-covered except for four craters, the Alaska Volcano Observatory says.
The last known eruption for Tanaga was in 1914. It erupted twice in the late 1700s and again in 1829.
The observatory in a release said there are no known eruptions of Takawangha or Sajaka. However, field work has indicated that eruptions may have occurred from those volcanos and were attributed to Tanaga.
Eruption at Hawaii’s Kilauea volcano stops after 61 days
This photo provided by the U.S. Geological Survey shows the inside of the summit crater of the Kilauea Volcano on Jan. 6, 2023. The latest eruption at Kilauea's summit on Hawaii's Big Island has paused after 61 days of volcanic activity. Hawaii News Now reports U.S. Geological Survey's Hawaiian Volcano Observatory scientists said Tuesday, March 7, 2023, that lava was no longer flowing on the crater floor of Halemaumau, where all recent volcanic activity had been confined.
MARK THIESSEN
Wed, March 8, 2023
ANCHORAGE, Alaska (AP) — A swarm of earthquakes occurring over the past few weeks has intensified at a remote Alaska volcano dormant for over a century, a possible indication of an impending eruption.
The Alaska Volcano Observatory raised the alert level to advisory status for Tanaga Volcano late Tuesday after the quakes became very vigorous.
“We started seeing a whole lot of earthquakes occurring, one after the other, several per minute,” said John Power, a research geophysicist with the U.S. Geological Survey stationed in Anchorage at the Alaska Volcano Observatory.
There have been hundreds of small earthquakes, none larger than magnitude 2.75, but they are concentrated beneath the summit of the volcano, he said.
“That indicates that we’re seeing significant unrest at the volcano,” Power said.
“Whether or not this will lead to an eruption is something we can’t say at this point in time,” he said. “But we are concerned about it enough that we have gone and elevated the warning level.”
While the increase causes concern, he said many times earthquake activity will drop off with no eruption.
“It’s anybody’s guess as to where this particular round of earthquake activity may end up,” he said.
The volcano is on an uninhabited island in the western Aleutians, about 1,250 miles (2,012 kilometers) southwest of Anchorage. There are no communities or structures there, but Adak, a city of about 170 residents on another island, is about 65 miles (105 kilometers) away and could see ashfall.
If the volcano were to erupt, the biggest threat would be to aircraft. The Aleutians are below the routes that jets fly between North America and Asia. Volcanic ash is angular and sharp and can cause an airplane engine to shut down. Previous eruptions had both ash clouds and viscous lava that moves very slowly away from the mountain, much like what happened at Mount St. Helens in Washington state in 1980.
“It’s very different than what you would see, for example, in Hawaii, Kilauea or Mauna Loa, where you see these beautiful red rivers of lava flowing down the side of the volcano," Power said.
Tanaga is actually part of a three-volcano complex on the island. It’s the tallest of the three at 5,925 feet (1,806 meters). It sits in the middle, with Sajaka, a 4,443-foot volcano to its west. Sajaka had an older cone that collapsed into the North Pacific Ocean with a new cone that has emerged.
To the east of Tanaga is Takawangha, a 4,75-foot (1,449-meter) volcano that is mostly ice-covered except for four craters, the Alaska Volcano Observatory says.
The last known eruption for Tanaga was in 1914. It erupted twice in the late 1700s and again in 1829.
The observatory in a release said there are no known eruptions of Takawangha or Sajaka. However, field work has indicated that eruptions may have occurred from those volcanos and were attributed to Tanaga.
Eruption at Hawaii’s Kilauea volcano stops after 61 days
This photo provided by the U.S. Geological Survey shows the inside of the summit crater of the Kilauea Volcano on Jan. 6, 2023. The latest eruption at Kilauea's summit on Hawaii's Big Island has paused after 61 days of volcanic activity. Hawaii News Now reports U.S. Geological Survey's Hawaiian Volcano Observatory scientists said Tuesday, March 7, 2023, that lava was no longer flowing on the crater floor of Halemaumau, where all recent volcanic activity had been confined.
(U.S. Geological Survey via AP, File)
Tue, March 7, 2023
HONOLULU (AP) — The latest eruption at Kilauea’s summit on Hawaii's has paused after 61 days of volcanic activity.
U.S. Geological Survey’s Hawaiian Volcano Observatory scientists said Tuesday lava was no longer flowing on the crater floor of Halemaumau, where all recent volcanic activity had been confined, Hawaii News Now reported.
No significant changes have been observed along the volcano’s rift zones. Scientists on Monday observed small “ooze-outs” of lava flowing sluggishly in the lava lake.
Officials said activity diminished in the afternoon, and by Tuesday, there was no active lava in the crater.
USGS said the reduction in activity was related to the “larger deflationary tilt drop” that began Feb. 17, a common process at Kilauea in which the ground deflates for hours or days. The drop in pressure can then cause eruptions to diminish.
Kilauea began erupting again Jan. 5 after scientists detected a glow within Halemaumau Crater. The latest eruption started after a nearly monthlong pause in activity.
Kilauea is one of the world’s most active volcanoes. A 2018 Kilauea eruption destroyed more than 700 homes.
Before the major 2018 eruption, Kilauea had been erupting since 1983, and streams of lava occasionally covered farms and homes. During that time, the lava sometimes reached the ocean, causing dramatic interactions with the water.
Tue, March 7, 2023
HONOLULU (AP) — The latest eruption at Kilauea’s summit on Hawaii's has paused after 61 days of volcanic activity.
U.S. Geological Survey’s Hawaiian Volcano Observatory scientists said Tuesday lava was no longer flowing on the crater floor of Halemaumau, where all recent volcanic activity had been confined, Hawaii News Now reported.
No significant changes have been observed along the volcano’s rift zones. Scientists on Monday observed small “ooze-outs” of lava flowing sluggishly in the lava lake.
Officials said activity diminished in the afternoon, and by Tuesday, there was no active lava in the crater.
USGS said the reduction in activity was related to the “larger deflationary tilt drop” that began Feb. 17, a common process at Kilauea in which the ground deflates for hours or days. The drop in pressure can then cause eruptions to diminish.
Kilauea began erupting again Jan. 5 after scientists detected a glow within Halemaumau Crater. The latest eruption started after a nearly monthlong pause in activity.
Kilauea is one of the world’s most active volcanoes. A 2018 Kilauea eruption destroyed more than 700 homes.
Before the major 2018 eruption, Kilauea had been erupting since 1983, and streams of lava occasionally covered farms and homes. During that time, the lava sometimes reached the ocean, causing dramatic interactions with the water.
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