The Crater Lake eruption

At sunset, the Crater Lake volcano in the Cascade Range in Oregon is shrouded in the smoke of a wild fire ignited by lightning strike.
The devastating eruption of the stratovolcano Mount Mazama 6900 years ago emptied the interior of the volcano. Under its own weight, the volcano collapsed into a ring structure eight kilometers (5 miles) wide and ten kilometers (6 miles) long. Later, this 1200 m (4000 ft) deep caldera filled up to half of its depth with rainwater and formed the deep-blue Crater Lake. The water color indicates the purity of the water.
Mount Mazama was about 4000 m (13.100 ft) tall and probably looked similar to today’s Mount Rainier. After the collapse, the present day brink of Crater Lake is at an altitude of 2200 m (7200 ft). It is beyond human experience to imagine a cataclysmic volcanic eruption destroying such a high volcano and leaving behind a 1200 m (4000 ft) deep hole.
Wizard Island is a volcanic island that grows out of Crater Lake and builds the third generation of the volcano after Mount Mazama and Crater Lake. If this growing lava dome does not explode again prematurely, it will one day completely fill the caldera and continue to grow into the next large stratovolcano.
The steep crater walls reveal that Mount Mazama was heavily glaciated before its blast into oblivion. Several deep notches are vertical cross sections of former U-shaped valleys in which the glaciers were located. These glaciers melted abruptly during the catastrophic eruption and intensified the explosion when ice and water came into contact with the lava.