Earthquakes in the Adirondacks: Why Seismic Activity is a Common Occurence
Seismic Activity in Upstate New York
Numerous Fault Lines Exist in the Adirondacks
Warrensburg residents were awakened Sunday morning August 25th to the startling sounds of shaking and rumbling from a magnitude 2.7 earthquake. Although no major damage had been reported, the United States Geological Survey states the Adirondack State Park is among the most seismically active area along the Eastern seaboard, where small quakes occur every three to four years.
The Adirondacks are somewhat of a contradiction according to The Sieve, an online natural science magazine. The mountain ranges are composed of some of the oldest rocks on the planet; yet they are one of the youngest in existence. The ancient rock, trapped in the earth’s crust, has been pushing their way through the newer rocks of the Appalachians for the past 15-20 million years.
“Formed when prehistoric continents collided to form a single and massive landmass, its rocks have since fallen deep into fractured valleys and risen once more,” wrote author akasprak from The Sieve. “They have formed the floors of ancient oceans, and they have withstood the extreme heat of deep burial. These are the rocks that are forcing their way to the surface as the Adirondacks. As they erode and the crust continues to rise, the deepest, oldest rocks are exposed.”
The Adirondacks are unlike any other mountain chain in the world. The difference is found in how mountains form in the first place. A Geological History of the Adirondacks claim that the Adirondacks are the only mountains in the eastern coast that aren’t geologically Appalachians. The disconnected peaks are very different compared to the ridge-connected peaks of the White Mountains or the Appalachians. The Adirondacks belong to a much older formation, which is huge that lies underneath half of Canada and extends down through the Thousand Islands region.
There are many fault lines caused by the major geological uplift of the region that run northeast-southwest through the Adirondacks. Almost all the passes and valleys in the High Peaks such as Ausable Valley, Hunters Pass, Lake Arnold Pass, Indian Pass, Avalanche Pass and the Johns Brook Valley contain faults that have weakened the bedrock. While erosion continues to expose more bedrock, new slides form on the sides of the taller peaks and sweep away large patches of soil and vegetation.
The mystery that baffles scientists is why the Adirondacks continue to rise. A popular theory, though difficult to test, according to The Sieve is that there is a hotspot under the mountain chain. A pocket of land mass is forced to rise, pushing the crust above the surface, which would explain why the Adirondacks are dome-shaped.
The last damaging earthquake registered magnitude 5 near Plattsburgh in 2002.
–Diana Denner is a Contributor to The Free George. Chart Courtesy of the New York State Museum
The Free George is the online magazine and visitors’ guide of Upstate NY, covering things from Albany to Lake Placid, including Saratoga, the Lake George region and the Adirondacks. Check out our City Blogs section for our extended coverage areas as well.
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