Landslides from the caldera rim formed debris fans and turbidity sediments on the lake bed. During this period, fumaroles and sources of thermal waters were common and remained active. After some time, the slopes of the caldera stabilized more or less, the streams restored the radial drainage system of the mountain and began to sprout dense forests in the arid landscape. It is estimated that 720 years were required to fill the lake until its current depth. Many of these events took place in a period in which the prevailing climate was less humid than the current. The Volcano retains certain hydrothermal activity on the lake bed, which suggests that at some point Mount Mazama may suffer a new eruption.
In the case of Crater Lake, the term Caldera is a very important one to understand. A collapse Caldera by subsidence or collapse, tend to be elliptical and large in dimensions; its mechanism is little known, but seems to be related to the rapid drain of shallowed magmatic chambers and fractures generated by the rise of very viscous