Lava Point, Akutan Island

Lava Point, Akutan Island

by | May 12, 2022

Lava Point is a headland on the northwest coast of Akutan Island consisting of about 988 acres (400 ha) of jagged basalt extruded during eruptions of Akutan Volcano, about 26 miles (42 km) northeast of Dutch Harbor and 12 miles (19 km) west-northwest of Akutan Village, Alaska. The descriptive name for the point was first reported in 1902 by the U.S. Coast and Geodetic Survey. Akutan Island is approximately 18 miles (29 km) long by 13 miles (21 km) wide and is the largest island in the Krenitzin Islands group in the eastern Aleutian Island arc. The island is dominated by Akutan Volcano, a composite stratovolcano with a circular summit caldera, about 1.2 miles (2 km) across and 200-1200 feet (60-365 m) deep, with an active caldera cinder cone. The caldera rim reaches a maximum elevation of 4,275 feet (1,303 m) at Akutan Peak, the remnant of a pre-caldera cinder cone now filled with a lava plug. The remains of a larger caldera dating to the late Pleistocene extend 0.9 miles (1.5 km) southwest of Akutan Peak and is terminated to the north by the younger caldera. Small glaciers fill the older crater and lie within the southwest and southeast margins of the younger caldera. The active caldera cinder cone is over 650 feet (200 m) high, about 0.6 miles (1 km) in diameter, and located in the northeast quarter of the caldera. Three small sulfur-lined craters occupy its summit and several fumarole zones are present along its south and southwest flank. A crescent-shaped lake along the inner southwest rim of the caldera and a hot and slightly acidic lake along the northern caldera wall were documented in 1948, but these lakes may have been obliterated by more recent volcanic activity. Much of Lava Point probably originated before 1870, but at least some of the flows formed in the late 1920s when Captain C. Anderson on the mail steamer Starr observed smoke near Lava Point, which may have issued from a large cinder cone at the base of Half Peak. In 1947, extruded lava flows blanketed the central portion of the northwest end of the island at Lava Point.

Other 20th-century volcanic activities on Akutan are better documented. In 1929, lava was observed flowing through the breach in the north caldera rim and extending about 0.4 miles (0.7 km) down the northeast flank. A mudflow produced at the front of this lava tongue flowed into valleys to the north and northwest. In 1931, dark smoke was observed above the caldera cinder cone. In 1947, lava extruded from a vent near the base of the caldera cone, and U.S. Navy vessels evacuated 75 island residents. In 1948, three earthquakes preceded a major eruption that covered Akutan village with measurable deposits of ash. Sporadic activity continued that year with clouds of ash-laden gas and fragments up to 3 feet (1 m) in diameter being ejected from the summit cone. Ash eruptions continued to be reported until 1953. More ash eruptions occurred in 1973 and 1974, and in 1977, clouds of light brown ash were ejected about every 15 minutes, with intervening periods of steam emission. In 1978, airline pilots observed fragments the size of cars being ejected 330 feet (100 m) above the summit and a lava flow on the summit cone that may have breached the north rim of the caldera. In 1980 and 1987, emissions of ash and steam were observed. In 1988, small ash eruptions began from the summit cinder cone and continued intermittently, and ashfall and strong sulfur fumes were reported at Akutan village. In 1989, the village reported a light dusting of ash, and then activity subsided until September 1990 when intermittent emissions of ash and steam plumes occurred and continued into 1991. The most recent eruptive activity from Akutan was during March through May 1992 and possibly into 1993 when localized steam and ash emissions with plumes rising up to 15,000 feet (4600 m) were reported. An intense earthquake swarm began beneath Akutan volcano in 1996 causing apprehension in Akutan village that an eruption might be imminent. There was a measurable deformation of the volcanic edifice including a lowering of the eastern side and a rise of the western side of the volcano. Fumarole activity at the base of Lava Point continues today and there is evidence from Hot Springs Bay on the northeast coast of the island that large changes have occurred in the hydrothermal system over the past 30 years.

Hot Springs Bay was named for the several dozen hot springs and a geyser present in the lower portion of the valley at the head of the bay. The hot springs occur in a band about 330 feet (100 m) wide that extends about 0.9 miles (1.5 km) up the valley from the sea. Hot springs located further up the valley generally have higher temperatures. Above the valley at an elevation of 1,370 feet (417 m), a vigorous fumarole field of about 2 acres (0.8 ha) is composed of four large and dozens of smaller gas vents at an elevation of 1,370 feet (417 m). The residents of Akutan have pursued the development of a geothermal resource for energy production since 2008. Akutan has potential for growth as a center of commerce and industry in the Aleutian chain, especially with a new harbor at the head of Akutan Bay, an airport on the adjacent Akun Island, and the largest land-based seafood processing facility in North America. The geothermal prospect in Hot Springs Bay valley has been extensively studied including geophysical surveys, geological mapping, geochemical studies, and drilling of three small diameter wells, two in 2010 and one in 2016. This confirmed there is a geothermal resource available at the hot springs area where the potential mean power capacity is 3 MWe and the most likely power capacity is 1 MWe. The fumarole area above the valley has a potential mean capacity of 20 MWe and the most likely capacity of 9 MWe. Work on development scenarios has also been completed, including the infrastructure needed for power generation, transmission and maintenance, and financial feasibility. The greatest probability of successful power production is in the fumarole area, but development is hampered by the inaccessible terrain. Though the indications of a higher temperature geothermal resource exist in this area, the higher cost of exploration, drilling, and development of this site is currently not justified for the electricity demand. Read more here and here. Explore more of Lava Point and Akutan Island here:

About the background graphic

This ‘warming stripe’ graphic is a visual representation of the change in global temperature from 1850 (top) to 2021 (bottom). Each stripe represents the average global temperature for one year. The average temperature from 1971-2000 is set as the boundary between blue and red. The color scale goes from -0.7°C to +0.7°C. The data are from the UK Met Office HadCRUT4.6 dataset. 

Credit: Professor Ed Hawkins (University of Reading). Click here for more information about the #warmingstripes.

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