This cataclysmic event of 7,700 years ago left us a legacy that is astounding to view and comprehend.
After 12,000-foot Mt Mazama's explosive eruption, the magma chamber beneath the mountain emptied, and the walls could no longer support the peak, and it simply collapsed and fell in, leaving a gigantic hole or caldera. Centuries of rain and snow filled the deep basin to become what we see today, a crater lake, the deepest, clearest and bluest in the US.
Another event followed when a new volcano formed and created a perfect cone island, Wizard Island, in the middle of the lake.
Next to the cataclysmic event that formed Yellowstone, Mt Mazama's eruption is considered to be a runner-up in magnitude and size.
Here are a few facts about Crater Lake:
- 6.02 miles across at the widest point
- 4.54 miles across at the narrowest point
- 1,943 feet deep at the deepest point
- holds 4.9 trillion gallons of water, an impressive amount considering that there are no streams that feed into the lake
- fish-free until fish were introduced in 1888
- tallest point on the rim is 1,978 feet above the lake
- lowest point on the rim is 507 feet above the lake
- 533 inches of snow falls yearly
To illustrate the scale of this event, here is some background. On the way to the National Park, along the road there is a plaque we stopped to read showing where Mt Mazama once stood before her cataclysmic eruption.
Here is a photo I took of the mountain ridges that remain today, minus Mt Mazama.
It offered good perspective to imagine the 12,000 foot volcano that once stood towering over this valley. Mt Mazama's snow covered peak would have been obscured by the clouds. All that remains today behind the existing ridges is the gigantic crater that is Crater Lake.
The ashfall from the eruption was enough to cover 5,000 sq miles with at least 6 inches to the north and east. Just north of Crater Lake, ash and pumice lie 50 feet deep. Ash scattered over eight states and three Canadian provinces. In fact, the eruption of Mt Mazama was 100 times greater than the May 18, 1980 eruption of Mt St Helens. We arrived in Washington State just a few weeks after that eruption, and saw ash still piled along the roadway when we were driving through eastern Washington.
The aerial view of the caldera must be impressive. All we had was the 3-D topographical rendition of this model:
We drove the 33-mile circle route around the rim, stopping for gorgeous views and learning a little more about the geological features found in and around the crater. But first we stopped at the Visitor Center to watch their informative movie. Afterward, with a Crater Lake patch (for me) and a National Parks centennial cap (for him) in hand, we headed off along the west rim road.
We learned about fossilized steam which created the many fossil fumaroles we saw rising out of canyons.
These spires formed when steam and gases were released through vents and hardened like cement. Centuries of erosion revealed the pinnacles we see today.
Here is more about these volcanic pinnacles: http://www.craterlakeinstitute.com/planning-visit/activities/trail-pinnacles-valley.htm
The angled cliff in the photo below is Llao Rock, a portion of the hardened lava flow that remains perched on the crater rim after it cracked and dropped.
The ashfall from the eruption was enough to cover 5,000 sq miles with at least 6 inches to the north and east. Just north of Crater Lake, ash and pumice lie 50 feet deep. Ash scattered over eight states and three Canadian provinces. In fact, the eruption of Mt Mazama was 100 times greater than the May 18, 1980 eruption of Mt St Helens. We arrived in Washington State just a few weeks after that eruption, and saw ash still piled along the roadway when we were driving through eastern Washington.
The aerial view of the caldera must be impressive. All we had was the 3-D topographical rendition of this model:
We drove the 33-mile circle route around the rim, stopping for gorgeous views and learning a little more about the geological features found in and around the crater. But first we stopped at the Visitor Center to watch their informative movie. Afterward, with a Crater Lake patch (for me) and a National Parks centennial cap (for him) in hand, we headed off along the west rim road.
We learned about fossilized steam which created the many fossil fumaroles we saw rising out of canyons.
These spires formed when steam and gases were released through vents and hardened like cement. Centuries of erosion revealed the pinnacles we see today.
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| fascinating pinnacles in all shapes and size |
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| these pinnacles can be as tall as 100 feet |
The angled cliff in the photo below is Llao Rock, a portion of the hardened lava flow that remains perched on the crater rim after it cracked and dropped.
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| this reader board illustrates Lao Rock's formation |
Crater Lake is renowned for its pure, blue water. Visibility to a depth of 144 feet was recorded in 1972. Today this is what we saw over the crater's edge:
Here are several more shots from various vantage points along the rim. It was simply too difficult to choose only a couple...
Of course, the ancient native people lived here at the time of the eruption. The tale of the origins of Crater Lake has been passed down through the generations amongst the Klamath. It parallels the geologic events that occurred in the area.
The legend is told here: http://www.craterlakeinstitute.com/crater-lake-news/how-crater-lake-came-to-be.htm
During excavations begun in 1938, tools and several pairs of woven sandals were unearthed, dating back to between 9 and 10 thousand years ago. They were buried beneath a thick layer of ash.
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| reproduction of bark sandals found at Fort Rock Cave |
We plan to continue the National Parks' Centennial celebration by visiting several more parks as we continue to make our way further south. Stay tuned....