Crater Lake: June 2010


This year, when we got to the south cascade mountains, they had been hammered by snow for several days. Unfortunately, immediately following that, there were a few days of really warm weather resulting in some serious avalanche danger on Mount Hood. Since the avalanche danger prevented us from climbing the big peak, we took a detour and checked out Crater Lake, which my boy Michael Reeves had told me about a few years back. While we were disappointed to not be able to bag Hood, this was a cool alternative.

This water was the bluest water I have ever seen. And you can't even imagine how big this thing is. When this thing errupted, I'm sure it was a show.

Crater Lake is a caldera lake located in the south-central region of the U.S. state of Oregon. It is the main feature of Crater Lake National Park and famous for its deep blue color and water clarity. The lake partly fills a nearly 2,148 foot (655 m) deep caldera that was formed around 7,700 (± 150) years agoby the collapse of the volcano Mount Mazama.

On June 12, 1853, John Wesley Hillman was reportedly the first White to see what he named "Deep Blue Lake" in Oregon. The lake was renamed at least three times, as Blue Lake, Lake Majesty, and finally Crater Lake.

Crater Lake is known for the "Old Man of the Lake", a full-sized tree which is now a stump that has been bobbing vertically in the lake for more than a century.Due to the cold water, the tree has been rather well preserved.

While having no indigenous fish population, the lake was stocked from 1888 to 1941 with a variety of fish. Several species have formed self sustaining populations.

Dimensions and depth

The lake is 5 by 6 miles (8 by 10 km) across with an average depth of 1,148 feet (350 m). Its maximum depth has been measured at 1,949 feet (594 m),which fluctuates slightly as the weather changes. This makes Crater Lake the deepest lake that is completely in the United States, the second deepest lake in North America, and the ninth deepest lake in the world.

However, on the basis of comparing average depths among the world's deepest lakes, Crater Lake becomes the deepest lake in the Western Hemisphere and the third deepest in the world.Comparing average depths among the world's lakes whose basins are entirely above sea level, Crater Lake is the deepest.

The caldera rim of Crater Lake ranges in elevation from 7,000 to 8,000 feet (2,100 to 2,400 m).

 

Geology

Mount Mazama, part of the Cascade Range volcanic arc, was built up mostly of andesite, dacite, and rhyodacite over a period of at least 400,000 years. The caldera was created in a massive volcanic eruption that led to the subsidence of Mount Mazama around 5700 BC: about 50 cubic kilometers (12 cubic miles) of rhyodacite was erupted in this event. Since that time, all eruptions on Mazama have been confined to the caldera.

Lava eruptions later created a central platform, Wizard Island, Merriam Cone, and other, smaller volcanic features, including a rhyodacite dome that was eventually created atop the central platform. Sediments and landslide debris also covered the caldera floor.

Eventually, the caldera cooled, allowing rain and snow to accumulate and eventually form a lake. Landslides from the caldera rim thereafter formed debris fans and turbidite sediments on the lake bed. Fumaroles and hot springs remained common and active during this period. Also after some time, the slopes of the lake's caldera rim more or less stabilized, streams restored a radial drainage pattern on the mountain, and dense forests began to revegetate the barren landscape. It is estimated that about 720 years was required to fill the lake to its present depth of 594 m. Much of this occurred during a period when the prevailing climate was less moist than at present.

Some hydrothermal activity remains along the lake floor, suggesting that at some time in the future Mazama may erupt once again.

Water quality

Due to several unique factors, most prominently that it has no inlets or tributaries, the waters of Crater Lake are some of the purest in terms of the absence of pollutants in North America.

Secchi disk clarity readings have consistently been in the high-20 meter to mid-30 meter (80–115 ft) range, which is very clear for any natural body of water. In 1997, scientists recorded a record clarity of 43.3 meters (142 ft).


"A human being should be able to change a diaper, plan an invasion, butcher a hog, conn a ship, design a building, write a sonnet, balance accounts, build a wall, set a bone, comfort the dying, take orders, give orders, cooperate, act alone, solve equations, analyze a new problem, pitch manure, program a computer, cook a tasty meal, fight efficiently, die gallantly. Specialization is for insects."    — Robert A. Heinlein

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