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What caused the Lituya Bay landslide?
Abstract. On July 10, 1958, an earthquake Mw 8.3 along the Fairweather fault triggered a major subaerial landslide into Gilbert Inlet at the head of Lituya Bay on the southern coast of Alaska. The landslide impacted the water at high speed generating a giant tsunami and the highest wave runup in recorded history.
What damage did the Lituya Bay tsunami cause?
Some 2 square miles (4 square kilometers) of forest were sheared and swept away by the tsunami waves. One of the causes of the enormous waves in Lituya Bay was that an entire chunk of a mountain peak—estimated to be 2,400 feet by 3,000 feet by 300 feet—broke free from a cliff and dropped 2,000 feet.
What’s the tallest tsunami ever recorded?
The megatsunami in Spirit Lake, Washington, USA that was caused by the 1980 eruption of Mount St. Helens reached 260 metres (853 ft), while the tallest megatsunami ever recorded (Lituya Bay in 1958) reached a run-up height of 520 metres (1,720 ft).
How big was the Lituya Bay earthquake?
The strike-slip earthquake took place on the Fairweather Fault and triggered a rockslide of 40 million cubic yards (30 million cubic meters and about 90 million tons) into the narrow inlet of Lituya Bay, Alaska.
How did Lituya Bay get so dangerous?
But it was in 1958 that Lituya Bay’s unpredictable waters reared up in truly apocalyptic fashion. After a 7.8 earthquake throttled the nearby Fairweather Fault, a rockslide sent 90 million tons of rock plunging into the bay—an amount equivalent to 8 million dump truck loads.
What caused the Lituya Bay tsunami?
The impact of 40 million cubic yards (30.6 million cubic meters) of rock hitting the water produced a local tsunami that swept the entire length of the Lituya Bay and over the La Chaussee Spit. This wave stripped all vegetation and soil from along the edges of the bay.
What was the Lituya Bay megatsunami?
The megatsunami flooded the entire bay and created a damage line up to 700 feet around the outline of the bay, with evidence of this damage line still visible from space to this day. At 22:15 hours PST on July 9, 1958, which was still daylight at that time of year, an earthquake with a magnitude of 7.8 struck the Lituya Bay area.