Under Trees and Water at Crater Lake National Park, Oregon

Home , Annie Falls, Crater Lake, Wizard Island

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U.S. Department of the Interior Scientific Investigations Map 3223 U.S. Geological Survey

INTRODUCTION C Crater Lake partially fills the caldera that formed approximately 7,700 years ago during the eruption of a 12,000-ft-high volcano 138 known as Mount Mazama. The caldera-forming, or climactic, eruption of Mount Mazama devastated the surrounding landscape, Tiny Creek left a thick deposit of pumice and ash in adjacent valleys, and spread a blanket of volcanic ash as far away as southern Canada. C1 Prior to the climactic event, Mount Mazama had a 400,000-year history of volcanic activity similar to other large Cascade volca- 209 Mazama noes such as Mounts Shasta, Hood, and Rainier. Since the caldera formed, many smaller, less violent eruptions occurred at volca- Creek nic vents below Crater Lake’s surface, including Wizard Island. A survey of Crater Lake National Park with airborne LiDAR Boundary Elevation (Light Detection And Ranging) resulted in a digital elevation map of the ground surface beneath the forest canopy. The average Springs Desert Ridge meters above Gaywas resolution is 1.6 laser returns per square meter yielding vertical and horizontal accuracies of ±5 cm. The map of the floor beneath sea level Peak C3 the surface of the 1,947-ft-deep (593-m-deep) Crater Lake was developed from a multibeam sonar bathymetric survey and was RED CONE SPRING FAULT 2,722 m added to the map to provide a continuous view of the landscape from the highest peak on Mount Scott to the deepest part of Crater C2 2,550 Lake. Four enlarged shaded-relief views provide a sampling of features that illustrate the resolution of the LiDAR survey and 2,350 C4 illustrate its utility in revealing volcanic landforms and subtle features of the climactic eruption deposits. LiDAR’s high precision Timber Klamath 2,150 and ability to “see” through the forest canopy reveal features that may not be easily recognized—even when walked over— Ridge Crescent Bald 1,950 because their full extent is hidden by vegetation, such as the 1-m-tall arcuate scarp (B4) near Castle Creek. Ridge Crater Crater 1,750

Desert 1,550 Cone 1,350 A Pumice 1,152 m Desert Desert Creek

Sharp A1 Crater 0 500 1,000 Feet N Springs Red Peak Red Grouse Cone 0 100 200 300 400Meters Sphagnum Cone Hill Bog Spring C. On the northeast edge of Crater Lake, the scallop-shaped view—caused the cooler, more ridged lava-flow surface to Bear Cleetwood Cove formed during the climactic eruption of sag and crack apart (C3). This opened up large rifts that can Butte Mazama Mount Mazama as the mountain foundered into the opening be seen adjacent to the Cleetwood Trail parking lot and Rim Rock Crater Creek Cleetwood caldera. Northeast of the cove is the Cleetwood rhyodacite Drive. The trail to the tour boat landing (C4) is visible zigzag- Llao Cove Bear Creek A5 Rock Steel Bay C lava flow (C1), which erupted as little as a few months before ging its way down the caldera wall. The white band separat- Pumice Palisade the climactic eruption. When the caldera collapsed, the lava ing bathymetry survey from LiDAR survey lacks precise eleva- Point Point Llao Roundtop flow still had a molten interior that oozed into the caldera, tion data in shallow water where bathymetric data were not A4 Bay Merriam Wineglass forming a rugged tongue between the high cliffs on either side collected. Parallel east-west apparent grooves on lake floor Merriam A3 Cone of Cleetwood Cove. The drainage of lava from the main flow and north-south stitching are artifacts of bathymetric data Point Grotto Williams Cascade Cove down the caldera wall (C2) and to the northeast—beyond this processing. Copeland Hillman Spring Creek Crater Peak A2 Crater Skell Head Pothole Creek The D central Bybee Creek Watchman Wizard Lake Pothole Scott Bluffs 0 750 Feet N platform Cloudcap Spring Island 0 100 200 300 Meters A Bay Cloudcap Sentinel Rock A. Wizard Island (A1) rises from the floor of the lake to 760 ft lake when the lake level was lower. A series of these older, Discovery Mount (233 m) above Crater Lake’s surface. The island is made of drowned shorelines help us understand the lake filling Point Scott andesitic lava and scoria (dark, frothy ejected lava) erupted history. The white band (A4) surrounding Wizard Island lacks Eagle Eagle Anderson Cove Danger Bay Spring approximately 7,000 years ago as the lake was filling to precise elevation data in shallow water where bathymetric Point Phantom Kerr Notch almost its present level. Lava flows with marginal levees (A2) data were not collected. The Wizard Island boat dock can be Chaski Ship Garfield Bay Anderson Bluffs ANNIE SPRING FAULT surround the cinder cone and can be followed from the seen on the island’s southern shore to the east of a large Sun Notch high-resolution LiDAR data into the lower-resolution bathym- leveed lava flow. The Wizard Island foot trail (A5) winds its Peak Applegate 62 etry beneath the lake's surface. Farther offshore are way through the forest going up the south side of the cinder Peak drowned lava deltas (A3) that formed as lava flowed into the cone. Little Castle Creek D1 B D Castle Creek Thousand D2 B Springs Castle Cavern Creek

B1 Union Creek Point Sand Creek

Munson Valley Whitehorse Wheeler Creek Bluff

Maklaks Pass Grayback Ridge

Arant B4 0 500 1,000 1,500 Feet N Point Crater The Pinnacles B2 0 250 500 Meters B3 Annie Creek Peak Sun Creek D. Sharp Peak (D1) is the largest of 12 rhyodacite lava domes toward the valley center, where the deposit is thickest. The

Maklaks that erupted about 18,000 years ago to the northeast of the tilting of the deposit’s surface pulled it away from the high- Union Bear 62 caldera. The linear trend of the domes suggests they erupted land south-southwest of Sharp Peak. In the southwest Crater Bluff along a radial fracture created by Mount Mazama. Just to the quarter of the image, running water rapidly carved parallel Peak north of Sharp Peak is a long northeast-trending rift (D2) northeast-trending gullies into the loose surface of the found in the climactic pyroclastic-flow deposit. The rift climactic pyroclastic-flow deposit. The LiDAR reveals many

Sand Ridge opened as the deposit compacted and tilted to the north features like this within Crater Lake National Park. Pumice Annie Falls

Flat

DATA SOURCES Robinson, J.E., 2012, Digital topographic map of Crater Lake National Park and vicinity, Oregon, based on LiDAR survey of August–September 2010, and bathymetric survey of July 2000: U.S. Geological Survey Data Series DS 716, (Available at 0 500 1,000 Feet N B5 http://pubs.usgs.gov/ds/716.) 0 100 200 300 400 Meters Gardner, J.V., and Dartnell, Peter, 2001, 2000 multibeam sonar survey of Crater Lake, Oregon; Data, GIS, images, and movies: 1 0 1 2 3 4 MILES OREGON U.S. Geological Survey Digital Data Series DDS–72, (Available at http://geopubs.wr.usgs.gov/dds/dds-72.) B. Two creeks, Little Castle and Castle, flow through gorges at the nose of Castle Point scars the surface of this deposit. 1 0 1 2 3 4 KILOMETERS cut into Mount Mazama’s climactic pyroclastic-flow deposit. After deposition, the deposit began to compact because of ADDITIONAL READING The deposit formed from a mixture of hot gas, pumice, and ash cooling and settling. The rift opened as the deposit tilted away MAP LOCATION Bacon, C.R., 2008, Geologic map of Mount Mazama and Crater Lake caldera, Oregon: U.S. Geological Survey Scientific Investi- that moved rapidly down the slopes of Mount Mazama and from the point toward the deposit’s thickest part at the valley gations Map 2832, 4 sheets, scale 1:24,000, 45 p. pamphlet (Available at http://pubs.usgs.gov/sim/2832/.) into adjacent valleys. At the confluence of the creeks (B1), the center, where compaction was the greatest. A 1-m-tall Bacon, C.R., and Lanphere, M.A., 2006, Eruptive history and geochronology of Mount Mazama and the Crater Lake region, climactic pyroclastic-flow deposit is about 330 ft (100 m) thick. arcuate scarp (B4) faces west, where the margin of a pyro- Oregon: Geological Society of America Bulletin, v. 118, p. 1331–1359. Through the forest cover, LiDAR reveals features on the clastic flow deposit became unstable, collapsed, and fed a Bacon, C.R., Gardner, J.V., Mayer, L.A., Buktenica, M.W., Dartnell, Peter, Ramsey, D.W., and Robinson, J.E., 2002, Morphology, surface of this deposit. Many thinner flow deposits have thin secondary pyroclastic flow to the northwest. South of volcanism, and mass wasting in Crater Lake, Oregon: Geological Society of America Bulletin, v. 114, p. 675–692. finger-shaped flow lobes (B2). One prominent pyroclastic- Castle Point are crater vents for young basaltic flows, one flow deposit extends past Castle Point and banks in against it round and one pear shaped (B5). The basalt erupted after the and a low ridge of glacial deposits. At the toe of this flow are glaciers retreated, but before the Mazama climactic eruption, a series of finger-shaped flow lobes. An extensional rift (B3) between about 13,000 and 7,700 years ago. Under Trees and Water at Crater Lake National Park, Oregon

Any use of trade, product, or firm names in this publication is for descriptive By purposes only and does not imply endorsement by the U.S. Government For sale by U.S. Geological Survey, Information Services, Box 25286, Federal Center, Denver, CO 80225, 1–888–ASK–USGS Joel E. Robinson,1 Charles R. Bacon,1 and Chris Wayne2 Digital files available at http://pubs.usgs.gov/sim/3223/ 1 Suggested citation: Robinson, J.E., Bacon, C.R., and Wayne, Chris, 2012, Under U.S. Geological Survey, Menlo Park, California trees and water at Crater Lake National Park, Oregon: U.S. Geological Survey 2 National Park Service, Crater Lake, Oregon 2012 Printed on recycled paper Scientific Investigations Map 3223 (http://pubs.usgs.gov/sim/3223/).