Black Peak (Alaska) facts for kids
Quick facts for kids Black Peak |
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| Highest point | |
| Elevation | 3,385 ft (1,032 m) NGVD 29 |
| Listing | List of volcanoes in the United States |
| Geography | |
 Black Peak
Location in Alaska
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| Location | Alaska Peninsula, Alaska, United States |
| Topo map | USGS Chignik C-3 |
| Geology | |
| Formed by | Subduction zone volcanism |
| Mountain type | Stratovolcano |
| Volcanic arc | Aleutian Arc |
| Last eruption | 1900 BCE ± 150 years |
Black Peak is a fascinating, ancient stratovolcano located on the Alaska Peninsula in the U.S. state of Alaska. This mountain is also known by other names like Purple Crater, Black Volcano, or Sopka Chornaia. It stands tall within the Lake and Peninsula Borough, a region known for its wild and beautiful landscapes.
Contents
Exploring Black Peak: A Stratovolcano
Black Peak is a type of volcano called a stratovolcano. Imagine a giant, cone-shaped mountain built up over many years. Stratovolcanoes are formed by layers of hardened lava, volcanic ash, and rock fragments from past eruptions. They often have steep slopes and a crater at the top.
What Does "Eroded" Mean for a Volcano?
The article mentions Black Peak is "highly eroded." This means that over thousands of years, natural forces like wind, rain, and ice have worn away parts of the volcano. This process can change its shape and reveal its inner structure, making it look rugged and ancient. Black Peak also has a "lava dome complex," which is a mound-shaped structure formed when thick, sticky lava slowly oozes out of a volcano and piles up around its vent.
Where is Black Peak Located?
Black Peak is found on the Alaska Peninsula, a long strip of land that extends from mainland Alaska into the Pacific Ocean. This area is part of the famous Aleutian Arc, a chain of volcanoes that stretches across the northern Pacific. Its exact coordinates are 56.5530556° N latitude and 158.7866667° W longitude.
Black Peak's Powerful Past: A Giant Eruption
Black Peak had a very powerful eruption a long, long time ago. Scientists estimate this last big event happened around 1900 BCE. This eruption was so strong that it created a large, bowl-shaped hollow called a caldera at the volcano's summit.
Understanding the Volcanic Explosivity Index (VEI)
Volcanologists, who are scientists who study volcanoes, use something called the Volcanic Explosivity Index (VEI) to measure how big and explosive an eruption was. It's like a scale from 0 to 8. Black Peak's last eruption was a VEI-6. To give you an idea, a VEI-6 eruption is considered very large and explosive, much bigger than most everyday eruptions you might hear about. It means a huge amount of ash and rock was thrown into the air.
Ash Flows and Deposits
During this massive eruption, fast-moving clouds of superheated ash, gas, and rock fragments, known as "ash flows" or "pyroclastic flows," rushed down the sides of the volcano. These flows traveled into the Ash Creek and Bluff Creek valleys. They left behind thick layers of material, called "tuffs" and "block and ash flow deposits," that were up to 100 meters (about 328 feet) deep! Imagine entire valleys filled with volcanic debris from one event.
The Aleutian Arc: A Chain of Volcanoes
Black Peak is part of the Aleutian Arc, a curved chain of volcanoes that forms where two of Earth's giant tectonic plates meet. One plate is sliding beneath another in a process called subduction. This movement causes rocks to melt deep underground, creating magma that rises to the surface and forms volcanoes. The Aleutian Arc is home to many active and inactive volcanoes, making it a very dynamic part of the world.
See also
In Spanish: Black Peak para niños
