| This view from the Rim Village area on Crater Lake's south
rim shows Wizard Island, a volcano that built up in the caldera after the
massive eruption about 7,700 years ago that destroyed Mount Mazama. Llao
Rock is the massive cliff on the north rim of the lake (to the right of
Wizard Island). The high cliff consists of dense lava that poured from a
volcanic vent on the north side of the volcano before the eruption and collapse
of the volcano. Crater Lake is the deepest lake in North America (1,943
feet deep). The lake is a closed basin -- it has no surface outlet. The
average amount of water flowing into the lake equals the average amount
lost to groundwater discharge through the porous and permeable deposits
that formed the ancient volcano. The lake water in considered some of the
purest in the world (see Klimasauskas and others, 2002; Ramsey and others, 2000). |
