Basic Plate Information
The Aleutian Islands formed when the North American and Pacific plates collided about 70 million years ago. The resulting trench is over 7600 meters deep in some places. The plate boundaries are convergent, meaning that they hit each other, the oceanic crust sunk down and volcanic islands were formed. The islands are found on the North American Plate. They sit near where the North American Plate and the Pacific Plate meet. The Pacific Plate subducts under the North American Plate, causing active volcanoes. Volcanic eruptions and earthquakes are common. The Aleutian Islands are home to some of the most powerful storms on record and the islands get over 300 days of cloudy weather each year.
Earthquakes
- 1946 Aleutian Island earthquake: It was a magnitude 7.8 earthquake, had an epicenter of 52.8° N, 163.5° W, that caused a tsunami with waves from 45 ft-130 ft. It caused $26 million of damage. Date: April 1st, 1946.
- The 1957 Andreanof Islands Earthquake: On March 9, 1957, the Aleutian Islands suffered a magnitude 8.3 earthquake. However, the resulting tsunami was smaller than the 1946 earthquake. The tsunami reached Hawaii and caused some damage, but not much. The center was at 51.5 N, 175.7 W.
Continental Drift
This picture illustrates what happens in continental drift. Continental drift is the theory that all the continents were once joined together to create Pangaea. This "super-continent" was believed to have been formed during the creation of the earth. Due to continental drift, the gradual movement of the continents across the earth's surface over time, the continents are believed to have split apart.
World Map Interactive, "Continental Drift"
Seafloor spreading
Seafloor spreading is when tectonic plates spread apart and magma rises to the surface of the oceanic crust, pushing the seafloor apart (spreading). When this happens, the magma almost immediately cools and forms new igneous rock at the bottom of the ocean. Thanks to this, the Atlantic ocean is slowly growing, and the Pacific is slowly shrinking.
Mail.Colonial, "Plate Tectonics Theory"
TEctonic movement (Alaska Megathrust)
What is so good about this tectonic activity?
You may ask yourself, "If all these things are happening, why do I want to go to this place?", well, the answer is, the tectonic activity has caused this place to be gorgeous. The mountain views are out of this world and the volcanoes are the coolest things ever (literally).