The Mount Rainier and its extraordinary ecological variety


The Mount Rainier and its extraordinary ecological variety
© Craig Mitchelldyer / Stringer Getty Images News

Mount Rainier is a stratovolcano that is part of the Cascade Volcanic Arc and is capable of releasing lava flows, lahars, and pyroclastic flows. Its earliest volcanic deposits are estimated to be more than 840,000 years old and fall within the Lily Formation.

The mountain ecosystem is very varied, especially due to the fact that the climate varies depending on the different altitudes. The scientists proceeded to catalog the living beings found in the forest area, in that of the alpine plain and the nival plain, tracing more than 1,000 plants and fungi.

As for fauna, the mountain is home to 65 species of mammals, 5 of reptiles, 182 of birds, 14 of amphibians and 14 of native fish, as well as an innumerable quantity of invertebrates. Usually, 3-4 tremors are recorded every month near the summit, while occasionally swarms of 5-10 shallow earthquakes occur over two to three days, mostly within 4 km below the summit.

Such earthquakes are believed to be caused by the circulation of warm fluids beneath Rainier. In the same vein, presumably, such fluids also generate warm springs and steam vents within Mount Rainier National Park.

Mount Rainier© Samuel Corum / Stringer Getty Images news

The volcano is highly eroded, with glaciers on its slopes, and appears to be composed mainly of andesite.

Rainier likely once stood even higher than it does today, reaching about 15,000 feet (4,900 m), before massive lahars reduced its elevation nearly 5,000 years ago. After that period, Rainier continued to shed debris and lahars in its subsequent eruptions, the scope of which was probably very large due to the large amount of glacial ice present in the vicinity of the crater.

In fact, traces of lahars emitted as far as Puget Strait, about fifty kilometers away, are found. Shortly after 5,000 years ago, a large chunk of the volcano once again shattered and broke away from the main cone, ending up dragged to where Tacoma stands today, south of Seattle.

Mount Rainier's protection as a national park protects its ecosystem, providing a congenial habitat for many species in the region, including endemic flora and fauna such as the Cascade red fox and the Pedicularis rainierensis species.