U.S. Geological SurveyOpen-File Report 00-043, Version 2.0  

Bathymetric, Geophysical and Geologic Sample Data from Medicine Lake, Siskiyou County, Northern California 

by 

Jonathan R. Childs (1), Jacob B. Lowenstern (2) , R. Lawrence Phillips (1), Patrick Hart (1), James J. Rytuba (3), John A. Barron (2), Scott W. Starratt (2), and Sarah Spaulding (4)    

Open File Report 00-043

2000

This report is preliminary and has not been reviewed for conformity with U.S. Geological Survey editorial standards or with the North American Stratigraphic Code. Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Government. 
-  U.S. DEPARTMENT OF THE INTERIOR 
- U.S. GEOLOGICAL SURVEY   
- 
- (1) Mail Stop 999, 345 Middlefield Road, Menlo Park, CA 94025 USA   
- (2) Mail Stop 910, 345 Middlefield Road, Menlo Park, CA 94025 USA   
- (3) Mail Stop 901, 345 Middlefield Road, Menlo Park, CA 94025 USA   
- (4) California Academy of Sciences, Dept. of IZ&G, Golden Gate Park,   San Francisco, CA 94118 USA  
- Contents:         
- A.         Introduction  B.         Bathymetric and geophysical program  C.         Sediment Coring program  D. Mercury         analysis  E.         Paleontologic analysis 
- F. List of         Tables 
- G. List of         Figures  H.         Contacts  I.         Acknowledgements 

Appendices:I.       Bathymetric and geophysical program field notes (observer       logs)II.       Summary of seismic reflection profile linesIII.       ASCII bathymetric data file
Figure A1: Location of Medicine Lake Volcano,     California.
Figure A2: Aerial view of Medicine Lake from the northeast. Photo by       Julie Donnelly-Nolan, USGS
About Medicine Lake in September       1999:      
Perimeter of Lake 

6213 m or 20,380 ft 

Area of Lake 

1.65 square km = 408 acres 

Volume of lake 

13,400,000 cubic meters = 3.5 billion gallons             = 10,860 acre-feet 

Elevation of lake surface 

2036m or 6680 feet 

Greatest depth 

46.4 m or 152.2 feet 

Mean depth 

7.3m or 23.9 feet 

Median depth 

4.9m or 16.1 feet       

IntroductionIn September, 1999, the U.S. Geological Survey acquired high-resolution bathymetry, seismic reflection profiles, and geologic sample data from Medicine Lake, a high altitude (2,036 m) lake located within the summit caldera/basin at Medicine Lake volcano (MLV), a dormant Quaternary shield volcano located in the Cascade Range, 50 km northeast of Mt. Shasta. It last erupted less than 1000 years ago.The purpose of this work was to assess whether sediments in the lake might provide a high-resolution record of the climate, volcanic and geochemical (particularly mercury) history of the region. We are still working with our data to assess whether the sediments are appropriate for further study. This report provides a summary of what we have learned to date.

Selected data products include:
- A  bathymetric   map  of the lake (in meters).   
- Another   map  with depth in feet.   
- Forty  high-resolution   seismic reflection profiles  of the lake, including   seventeen acquired along east-west tracks, and twenty-three acquired along   northeast-southwest tracks (see  map with   track lines ).   
- A  temperature   profile  of the lake at its deepest point.   
- A  perspective-view  of the lake bathymetry.   
- Descriptions of   nine sediment cores , ranging in depth from 10 to 100   cm, from various locations within the lake and surrounding environ.   
- Map of  sampling/coring  locations.   
- Mercury   analyses  of lakewater and sediment samples from the   lake bottom.   
- Description   of diatoms  and other microfossils found in lake water   and sediments.   
- Data for   Downloading 

Tables include:
- Table   1.  Information on   core locations and characteristics.   
- Table   2 . Mercury and   methyl mercury concentration in sediment from cores at Medicine Lake.   
- Table   3 . Analyses of   mercury and methyl mercury in sediment samples from core number 6.   
- Table   4 . Analysis of   mercury and methyl mercury in water from Medicine Lake.   
- Appendix   2 . Summary of   seismic-reflection profile lines.   
- Appendix   3 . ASCII   Bathymetric Data File. 

Figures include:
- Figure A1 .  Location map of Medicine Lake Volcano.   
- Figure A2 . Photo of Medicine Lake from the northeast.   
- Figure   A3 . Perspective view of the Medicine Lake highland   and surrounding region.   
- Figure   A4.  Perspective view of geology and topography around   Medicine Lake.   
- Figure   B1 : The Geopulse and Seistec sources towed behind   boat.   
- Figure   B2 : The Fast Eddy (Boston Whaler).   
- Figure   B3 : Map 1: Bathymetric map of Medicine Lake contoured at 5-m intervals ( also can be   downloaded ).   
- Figure   B4:  Map 2: Bathymetric map of Medicine Lake contoured   at 10-foot intervals ( also can be   downloaded ).   
- Figure   B5 : A 3-D perspective view of the lake bathymetry, as   seen from the SW.   
- Figure   B6:  Map 3: Track lines showing locations of seismic   profiles.   
- Figure   B7 : Representative seismic line (N-STrackline 210)   near deep hole in lake.   
- Figure   B8 : Highlight of Trackline 210.   
- Figure   B9 : Profile of temperature with depth in Medicine   Lake.   
- Figure   C1 : Stratigraphy summary.   
- Figure   C2 : Key to sedimentary structures.   
- Figure   C3 : Map of sample locations (for sediment   cores).   
- Figure   C4 : Photo of hammer core #3.   
- Figure   C5 : Photo of box core #6.   
- Figures   C7 (1-18): Stratigraphy and texture diagrams for cores   1-9.   
- Figure   E1 : Photo of the planktonic diatom Cyclotella.   
- Figure   E2 : Photo of benthonic diatom Navicula.   
- Figure   E3 : Photos of other planktonic diatoms.   
- Figure   E4 : Photos of other benthonic diatoms.   
- Figure   E5 : Photos of chrysophyte stomatocysts. 

Geographic location, geologic setting, and physiographic environment of the Medicine Lake volcanic region are described at:

http://vulcan.wr.usgs.gov/Volcanoes/MedicineLake/framework.htmlhttp://vulcan.wr.usgs.gov/Volcanoes/California/Maps/map_medlake_shasta.htmlhttp://vulcan.wr.usgs.gov/Volcanoes/MedicineLake/Maps/map_lavabeds.html

Contacts 

Jon Childs 

Jake Lowenstern

U.S. Geological Survey 

U.S. Geological Survey 

M/S 999 

M/S 910 

345 Middlefield Rd. 

345 Middlefield Rd. 

Menlo Park CA 94025 

Menlo Park CA 94025 

(650) 329-5195 

(650) 329-5238 

jchilds@usgs.gov

jlwnstrn@usgs.gov

Acknowledgements

We appreciate considerable logistical assistance from Jayne Biggerstaff, Dan Meza, Brad Reed and Randall Sharp of the U.S. Forest Service, Modoc National Forest. At the USGS, Julie Donnelly-Nolan and Duane Champion offered advice and geologic expertise. Gerald O'Brien and Larry Kooker kept the Fast Eddy and the geophysical surveying equipment in top working order and the field program running smoothly. This work was funded through the USGS Volcano Hazards, Mineral Resources, Earth Surface Dynamics and Coastal and Marine Surveys Programs as well as through a grant from the Office of the Chief Geologist.
Front | Coring | Mercury | Diatoms | Bathymetry
AccessibilityFOIAPrivacyPolicies and Notices

U.S. Department of the Interior | U.S. Geological SurveyURL: http://pubs.usgs.gov/of/2000/of00-043/Page Contact Information: GS Pubs Web ContactPage Last Modified: Tuesday, February 19, 2013, 01:46:16 PM