Are there other restless volcanoes in the United States today besides Long Valley Caldera?
Several. An increase in earthquake activity has been observed at Iliamna Volcano in the Cook Inlet region of Alaska since May, 1996. Airborne surveys in August and October 1996 showed increased CO2 emissions from the volcano. Modest increases in sulfur dioxide were also observed. The USGS is continuing to monitor Iliamna’s activity with the University of Alaska Fairbanks Geophysical Institute and the Alaska Division of Geological and Geophysical Surveys in a cooperative program at the Alaska Volcano Observatory. Also in Alaska, the Katmai region, which produced the Valley of Ten Thousand Smokes during a colossal eruption in 1912, has experienced swarms of small earthquakes in recent years. And Pavlof volcano has been erupting sporadically since September 1996 and remains restless. In Hawaii, the largest volcanic edifice on Earth, Mauna Loa, has been slowly swelling and producing earthquakes since its last eruption in 1984. At Yellowstone in northwest Wyoming, one of the largest active
