Earthquakes at 2 Alaska Volcanoes Could Signal Eruption

In this photo provided by the Alaska Volcano Observatory/US Geological Survey is the Tanaga Volcano near Adak, Alaska, on May 23, 2021. (Alaska Volcano Observatory/US Geological Survey via AP)
In this photo provided by the Alaska Volcano Observatory/US Geological Survey is the Tanaga Volcano near Adak, Alaska, on May 23, 2021. (Alaska Volcano Observatory/US Geological Survey via AP)
TT

Earthquakes at 2 Alaska Volcanoes Could Signal Eruption

In this photo provided by the Alaska Volcano Observatory/US Geological Survey is the Tanaga Volcano near Adak, Alaska, on May 23, 2021. (Alaska Volcano Observatory/US Geological Survey via AP)
In this photo provided by the Alaska Volcano Observatory/US Geological Survey is the Tanaga Volcano near Adak, Alaska, on May 23, 2021. (Alaska Volcano Observatory/US Geological Survey via AP)

A second volcano in remote Alaska is experiencing elevated earthquake activity this week, signaling an increased potential for eruption, officials said.

Earthquake activity near Takawangha Volcano increased over the past 48 hours and are continuing, Alaska Volcano Observatory officials said in a news release Thursday.

That volcano is west of Anchorage in the western Aleutian islands and about 5 miles (8 kilometers) from Tanaga Volcano, which scientists said earlier this week had seen intensified earthquake activity.

The Alaska Volcano Observatory raised the alert level to advisory status for Tanaga Volcano late Tuesday after the quakes became vigorous.

The observatory on Thursday raised the alert level to watch status for Takawangha Volcano.

Analysts at the observatory continue to monitor the situation closely. Up to several earthquakes per minute are occurring under Tanaga Island, where both volcanoes are located, the observatory said. The largest quake over the previous 24 hours was a magnitude 3.9 located under Tanaga Volcano.

No eruptive activity or signs of unrest was detected in satellite or other monitoring data.

The island is about 1,250 miles (2,012 kilometers) southwest of Anchorage. There are no communities there, but Adak, a city of about 170 people on another island, is about 65 miles (105 kilometers) away and could see ashfall.

If one of the volcanoes were to erupt, it could be a problem for aircraft. The Aleutians are below the routes that jets fly between North America and Asia. Volcanic ash is angular and sharp and can cause airplane engines to shut down. Past eruptions had both ash clouds and viscous lava that moves slowly, much like what happened at Mount St. Helens in Washington state in 1980.

No historical eruptions are known from Takawangha but field work shows recent eruptions have occurred and its possible historic eruptions attributed to Tanaga may instead have come from Takawangha, according to scientists.

The last eruption from Tanaga Volcano was in 1914.



Climate Change Causing More Change in Rainfall, Fiercer Typhoons, Scientists Say 

People and vehicles wade through the water along a street that was flooded by Typhoon Gaemi in Kaohsiung on July 25, 2024. (AFP)
People and vehicles wade through the water along a street that was flooded by Typhoon Gaemi in Kaohsiung on July 25, 2024. (AFP)
TT

Climate Change Causing More Change in Rainfall, Fiercer Typhoons, Scientists Say 

People and vehicles wade through the water along a street that was flooded by Typhoon Gaemi in Kaohsiung on July 25, 2024. (AFP)
People and vehicles wade through the water along a street that was flooded by Typhoon Gaemi in Kaohsiung on July 25, 2024. (AFP)

Climate change is driving changes in rainfall patterns across the world, scientists said in a paper published on Friday, which could also be intensifying typhoons and other tropical storms.

Taiwan, the Philippines and then China were lashed by the year's most powerful typhoon this week, with schools, businesses and financial markets shut as wind speeds surged up to 227 kph (141 mph). On China's eastern coast, hundreds of thousands of people were evacuated ahead of landfall on Thursday.

Stronger tropical storms are part of a wider phenomenon of weather extremes driven by higher temperatures, scientists say.

Researchers led by Zhang Wenxia at the China Academy of Sciences studied historical meteorological data and found about 75% of the world's land area had seen a rise in "precipitation variability" or wider swings between wet and dry weather.

Warming temperatures have enhanced the ability of the atmosphere to hold moisture, which is causing wider fluctuations in rainfall, the researchers said in a paper published by the Science journal.

"(Variability) has increased in most places, including Australia, which means rainier rain periods and drier dry periods," said Steven Sherwood, a scientist at the Climate Change Research Center at the University of New South Wales, who was not involved in the study.

"This is going to increase as global warming continues, enhancing the chances of droughts and/or floods."

FEWER, BUT MORE INTENSE, STORMS

Scientists believe that climate change is also reshaping the behavior of tropical storms, including typhoons, making them less frequent but more powerful.

"I believe higher water vapor in the atmosphere is the ultimate cause of all of these tendencies toward more extreme hydrologic phenomena," Sherwood told Reuters.

Typhoon Gaemi, which first made landfall in Taiwan on Wednesday, was the strongest to hit the island in eight years.

While it is difficult to attribute individual weather events to climate change, models predict that global warming makes typhoons stronger, said Sachie Kanada, a researcher at Japan's Nagoya University.

"In general, warmer sea surface temperature is a favorable condition for tropical cyclone development," she said.

In its "blue paper" on climate change published this month, China said the number of typhoons in the Northwest Pacific and South China Sea had declined significantly since the 1990s, but they were getting stronger.

Taiwan also said in its climate change report published in May that climate change was likely to reduce the overall number of typhoons in the region while making each one more intense.

The decrease in the number of typhoons is due to the uneven pattern of ocean warming, with temperatures rising faster in the western Pacific than the east, said Feng Xiangbo, a tropical cyclone research scientist at the University of Reading.

Water vapor capacity in the lower atmosphere is expected to rise by 7% for each 1 degree Celsius increase in temperatures, with tropical cyclone rainfall in the United States surging by as much as 40% for each single degree rise, he said.