An island that sprung up in Pakistan after a strong earthquake shook the area in 2013 has disappeared, swallowed up by the sea, new images released by NASA show.
The island, called Zalzala Koh (or “Earthquake Mountain” in Urdu), was located in a shallow bay near the Pakistani port city of Gwadar. It was the product of a mud volcano triggered by the earthquake in September 2013.
Geologists at the time predicted that the island, which measured 65 feet high, 295 feet wide, and 131 feet long, would be no match for the Arabian Sea’s waves and tides that would chip away at the muddy, silty feature.
They were right.
The series of images above shows the island in April and September 2013, November 2016, and April 2019. (Photo Credit: NASA Earth Observatory)
NASA’s Landsat satellites acquired images showing trails of mud and sediment discoloring the water around the island. By the end of 2016, not much terrain was left above the water line.
Satellite images indicated that the Arabian Sea was washing over the island at high tide, swallowing it up.
But even though “Earthquake Mountain” may be out of sight for now, it does not mean it is completely gone.
The island is seen here in Nov. 26, 2016. (Photo Credit: NASA Earth Observatory)
In 2019, hints of the island persist in Landsat imagery, according to NASA. As recently as June 2019, Landsat observed trails of sediment circulating around the submerged base.
In a blog post, NASA explains the formation of islands from mud volcanoes:
The mud volcanoes along Pakistan’s coast are a byproduct of plate tectonics. The Arabian plate is sinking beneath the Eurasian plate by a few centimeters per year. The process pushes soft sediments onto the edge of the Eurasian plate and become a key ingredient for mud volcanoes. Meanwhile the edge between the Arabian and Eurasian plates can heat up under the extreme pressure. Rocks melt into magma, and the magma and hot volcanic gases warm subsurface water enough to turn it into an acid capable of dissolving rock. Over time, this slurry of hot mud and gas seeps through underground cracks, occasionally finding its way to the surface and erupting.
Remnants of the island seen in April 27, 2019. (Photo Credit: NASA Earth Observatory)
Islands formed by mud volcanoes have been known to come and go.
About 75 miles to the east of Zalzala Koh, another small, circular mud island — Malan — has risen from the sea and eroded away four times (in 1945, 1999, 2010, and 2013) in the past century.
More on Geek.com:
- 35 Incredible Images of Earth’s Mountains and Volcanoes From Space
- 20 Amazing Images of National Parks From Space
- Stunning Images of a Sunset on Earth Captured By Astronaut in Space
The post Island Created By Earthquake Swallowed Up By Sea, NASA Images Show appeared first on Geek.com.
from Geek.com https://ift.tt/30iL17X
via IFTTT
0 comments:
Post a Comment