Amchitka facts for kids

Quick facts for kids Amchitka Underground Test Site
Cannikin warhead being lowered into test shaft
Location of the site
Coordinates	51°32′32″N 178°59′00″E / 51.54222°N 178.98333°E / 51.54222; 178.98333 (Amchitka Underground Test Site)
Type	Nuclear testing range
Site information
Operator	United States Department of Energy
Status	Inactive
Site history
In use	1965–1971
Test information
Thermonuclear tests	3
Remediation	2001–2025 (DoE estimate)

Amchitka (Aleut: Amchixtax̂; Russian: Амчитка) is a volcanic island in the Aleutian Islands of southwest Alaska. It is part of the Alaska Maritime National Wildlife Refuge. The island is about 42 miles (68 km) long and 1 to 4 miles (1.6 to 6.4 km) wide. It has a land area of about 116 square miles (300 km2).

Amchitka has a maritime climate with many storms. The skies are often cloudy. The island was home to the Aleut people for over 2,500 years. However, no one has lived there permanently since 1832.

The United States has owned Amchitka since the Alaska Purchase in 1867. During World War II, the US military used it as an airfield. This was important during the Aleutian Islands campaign.

Later, the United States Atomic Energy Commission chose Amchitka for underground nuclear weapons tests. Three large tests happened here:

• Long Shot (1965)
• Milrow (1969)
• Cannikin (1971)

Cannikin was the largest underground test ever done by the United States. It was a 5-megaton blast. These tests were very controversial. Many environmental groups worried about earthquakes and tsunamis. Amchitka is no longer used for nuclear testing. However, it is still watched for any radioactive leaks.

Amchitka's Geography

Amchitka Island, Harlequin Beach

Amchitka is the southernmost island in the Rat Islands group. These islands are part of the Aleutian Chain. The Bering Sea is to the north and east of the island. The Pacific Ocean is to the south and west.

The eastern part of the island is a flat area. It has small ponds and gentle hills. There is a lot of low-growing plant life. This includes mosses, ferns, grasses, and crowberry. The middle of the island is mountainous. The western end is mostly bare with few plants.

Amchitka has a maritime climate. It is often foggy and windy. Clouds cover the sky almost all the time. The ocean keeps temperatures mild, but storms are common. The island is volcanic and sits on a tectonically unstable area. This means it is one of the most geologically active places in the United States.

Aleutian cackling geese flying over Amchitka Island

Amchitka Island, beach fleabane in full bloom (Senecio pseudo-arnica)

Amchitka's Early History

People have lived on Amchitka for at least 2,500 years. The Aleut people were the first known inhabitants. In 1980, human remains were found. They are believed to be from an Aleut person who lived around 1000 AD.

Explorers like Vitus Bering and Joseph Billings sighted the island in the 1700s. In 1783, Daikokuya Kōdayū and 15 Japanese sailors landed on Amchitka. They had drifted for seven months after their ship was lost. Russian workers and local people helped them.

Amchitka in World War II

In June 1942, Japanese forces took over some western Aleutian islands. They also hoped to take Amchitka. The US military wanted to remove the Japanese quickly. They decided to build airfields west of Umnak. These airfields would allow bombers to attack the Japanese.

The US Army set up bases on Adak and other places. In September 1942, a team checked Amchitka. They found it would be hard to build an airstrip there. But military leaders decided the airfield "had to be built." This was to stop the Japanese from building one first.

American forces landed on Amchitka without a fight on January 12, 1943. Despite bad weather and Japanese bombing, the airfield was ready by February 16. This put the US military much closer to their target, Kiska. The military built many buildings, roads, and three airstrips on the island. One of these was later used by the Atomic Energy Commission. At its busiest, Amchitka had 15,000 troops.

The Aleutian Islands campaign ended successfully on August 24, 1943. After the war, the military bases on Amchitka closed. The last personnel left by the end of 1950.

Later, Amchitka hosted a White Alice telecommunication system. This was from 1959 to 1961. A special radar system was also there from 1991 to 1993. It was used to watch Russia.

Demographics

Amchitka appeared on the 1990 US Census with a population of 25. This was the only time it was listed as a populated place.

Nuclear Testing on Amchitka

Early Plans for Testing

The locations of the nuclear tests

After the military left Amchitka in 1950, the Department of Defense (DoD) thought about using it for nuclear tests. They wanted to learn how nuclear explosions created craters. But after drilling many test holes, the site was not suitable. The project moved to the Nevada Test Site.

In the late 1950s, scientists needed better ways to detect Soviet underground nuclear explosions. A test in Nevada called Rainier made strong seismic signals. But it looked like a normal earthquake. So, a program called Vela Uniform was started. Its goals were to improve seismic tools and study the seismic effects of nuclear blasts.

The DoD and the Atomic Energy Commission then looked at Amchitka again for the Vela Uniform tests.

Long Shot Test

This film still shows dirt being displaced from the Long Shot underground test.

The Long Shot test happened on October 29, 1965. The Department of Defense managed this test. The Atomic Energy Commission provided the nuclear device and scientific support. The main goal was to understand how nuclear explosions create seismic signals. They also wanted to tell them apart from natural earthquakes.

Alaskan officials were told about the test in February 1965. This was after the big Great Alaska earthquake in 1964. People were worried about how the test would affect them. But they were told it would be safe.

Long Shot was an 80-kiloton blast. It was the first underground test in a remote area. It was also the first test managed by the DoD. No surface collapse happened. However, small amounts of tritium and krypton were found at the surface later. This was not made public until 1969.

Milrow and Cannikin Tests

The Milrow test was done to study the island itself, not a weapon. It was a "calibration shot." This meant it was used to gather data. This data would help predict the effects of larger explosions. It was especially important for the planned Cannikin test. Milrow was detonated on October 2, 1969. Its yield was about 1 to 1.2 megatons.

The shockwave from Milrow made the ground rise about 5 meters (16 feet). This happened over an area about 3 kilometers (1.9 miles) wide. The blast also made the nearby sea foamy. It forced mud and water from streams and lakes 50 feet (15 m) into the air. A large hole, called a subsidence crater, formed as material collapsed into the space left by the explosion.

Cannikin was designed to test a powerful warhead. This warhead was for the Spartan anti-ballistic missile (ABM). The test aimed to measure the warhead's power. It also checked its design to make sure it was reliable.

Cannikin Tested

Cannikin was detonated on November 6, 1971. It was the largest underground nuclear test in US history. The announced yield was 5 megatons. This was almost 400 times more powerful than the Hiroshima bomb. The ground lifted 20 feet (6.1 m) from the force. A new lake formed at the site, hundreds of meters wide.

The explosion caused a seismic shock of 7.0 on the Richter scale. This caused rockfalls and turf slides. Environmental groups had predicted large earthquakes and tsunamis. These did not happen. However, some smaller tectonic events did occur in the weeks after. Scientists think these were due to the explosion affecting local stresses in the Earth's crust.

After 1973

The Atomic Energy Commission left the island in 1973. But scientists still visit to monitor the site. In 2001, the Department of Energy (DoE) returned to clean up environmental contamination. They stabilized old drilling mud pits. They covered them with special material, soil, and new seeds.

Some people worry that new cracks might be opening underground. This could allow radioactive materials to leak into the ocean. A 1996 study found small amounts of plutonium and americium leaking. However, studies in 2004 and 2006 found very low levels of plutonium. They said these levels were not harmful to living things.

The Department of Energy continues to monitor the site. This monitoring is expected to last until 2025. After that, Amchitka is planned to become a restricted wildlife preserve.

See also

In Spanish: Isla Amchitka para niños