Αποτελέσματα Αναζήτησης
Mount Mazama formed as a group of overlapping volcanic edifices such as shield volcanoes and small composite cones, becoming active intermittently until its climactic eruption 7,700 years ago. This eruption, the largest known within the Cascade Volcanic Arc in a million years, destroyed Mazama's summit, reducing its approximate 12,000-foot ...
31 Οκτ 2023 · By about 30,000 years ago, Mount Mazama began to generate increasingly explosive eruptions and thick flows of silica-rich rhyodacite lava. The change to more explosive and silica-rich eruptions was an outward sign that a large volume of silicic magma had begun to accumulate deep beneath the volcano.
23 Οκτ 2023 · The massive volcano erupted violently 7,700 years ago, accompanied by collapse of the entire upper half of the edifice. Prior to its climactic eruption Mount Mazama had a summit elevation of about 3,700 m (12,000 ft). The present high point is Mount Scott at 2,721 m (8929 ft), 3 km (about 2 mi) east of the caldera rim.
30 Οκτ 2023 · The climactic eruption of Mount Mazama devastated the terrain for tens of kilometers from the volcano, sent pyroclastic flows as far as 70 km (43 mi) down every valley heading on the volcano, and produced ash fall throughout much of the Pacific Northwest and parts of southern Canada.
1 Νοε 2006 · The Cascade arc volcano known as Mount Mazama collapsed during its climactic eruption of ∼50 km 3 of mainly rhyodacitic magma ∼7700 yr ago to form Crater Lake caldera. The Mazama edifice was constructed on a Pleistocene silicic lava field, amidst monogenetic and shield volcanoes ranging from basalt to andesite similar to parental magmas for ...
6 Δεκ 2022 · Mount Mazama, although its presence across the landscape lacks an exposed summit, is ranked 17th among the 161 potentially most dangerous volcanoes. About 4,800 years ago, a viscous rhyodacite dome nearly breached the lake surface. This is the youngest eruption product that has yet been recognized.
Mazama had its most destructive eruption about 7,700 years ago, spewing 12 cubic miles of rhyolite magma in the form of tephra as far north as Alberta, Canada, as far east as Wyoming and as far south as Nevada and northern California.
