border: A polygon shapefile that provides a generalized outline of the geographic area described by this report. alluvial-channels: Pre-eruption active alluvial and fluvial channels from field mapping and various source satellite imagery new-cone-crater-rim: Outline of new cone Ahmanilix's two crater rims, digitized from a September 22, 2008 Quickbird satellite image new-cone-region: Polygon depicting new cone Ahmanilix; digitized from a September 22, 2008 Quickbird satellite image. The base of cone was digitized from apparent break in slope as interpreted from the September 22, 2008 Quickbird image. Subsequent erosion has changed the shape of the cone dramatically. new-craters: Explosion crater rims and collapse crater rims as interpreted from fieldwork, post-eruption satellite images, and syn-eruption Synthetic Aperture Radar (SAR) imagery. new-pits: Polygons outlining syn-eruptive collapse pits; digitized from a September 22, 2008 Quickbird satellite image. new-vents: Approximate vent locations interpreted from fieldwork, post-eruption satellite images, and syn-eruption Synthetic Aperture Radar (SAR) imagery. Exact vent locations are uncertain, but are generally interpreted to lie within the region encompassed by the polygon feature. post-2008-eruption-lakes: Polygons outlining areas of surface water after the 2008 eruption; digitized from a September 22, 2008 Quickbird satellite image. pre-2008-eruption-lakes: Polygons outlining areas of surface water before the 2008 eruption; digitized from September 2000 IKONOS and August 2000 Landsat satellite imagery. stations: Field sites visited in August and September of 2008; locations were acquired with hand-held GPS units.
Larsen, J.F., Neal, C.A., Schaefer, J.R., Kaufman, A.M., and Lu, Zhong, 2015, The 2008 phreatomagmatic eruption of Okmok Volcano, Aleutian Islands, Alaska: Chronology, deposits, and landform changes: Report of Investigation RI 2015-2, Alaska Division of Geological & Geophysical Surveys, Fairbanks, Alaska, United States.Online Links:
This is a vector data set.
Planar coordinates are encoded using coordinate pair
Abscissae (x-coordinates) are specified to the nearest .01
Ordinates (y-coordinates) are specified to the nearest .01
Planar coordinates are specified in Meters
The horizontal datum used is World Geodetic System of 1984.
The ellipsoid used is WGS 84.
The semi-major axis of the ellipsoid used is 6378137.
The flattening of the ellipsoid used is 1/298.257223563.
Notes in the comment field may include feature labels or additional description. If present, blank or null values indicate that labels or additional information were not applicable.
Notes in the comment field may include feature labels or additional description. If present, blank or null values indicate that labels or additional information were not applicable.
Notes in the comment field may include feature labels or additional description. If present, blank or null values indicate that labels or additional information were not applicable.
Notes in the comment field may include feature labels or additional description. If present, blank or null values indicate that labels or additional information were not applicable.
Features were classified as "lake" or "water."
Notes in the comment field may include feature labels or additional description. If present, blank or null values indicate that labels or additional information were not applicable.
Unique station id values; the numbering convention is determined by the geologist who provided the description.
| Range of values | |
|---|---|
| Minimum: | 31-Jul-08 |
| Maximum: | 16-Sep-08 |
| Units: | DD-Mon-YY |
| Value | Definition |
|---|---|
| NULL | Blank (NULL) values indicate that tephra thickness was not measured at the station or that tephra observations were not applicable to that location. |
| Range of values | |
|---|---|
| Minimum: | 0.2 |
| Maximum: | 1230 |
| Units: | Centimeters |
Notes in the comment field provide additional description of the location or indicate the type of measurement, sample, or work that was conducted that the station.
We dedicate this Report of Investigations to Lonnie Kennedy and the Kennedy family of the Bering Pacific Ranch at Fort Glenn, in appreciation for their generous assistance during our field campaigns, and keen observations of Okmok volcano before, during, and after the 2008 eruption. The authors thank the Kennedy family for permission to use Lonnie's photographs and observations. Rick Wessels and Russ Rykhus are gratefully acknowledged for assistance with FLIR and SAR image acquisition and processing. We also thank helicopter pilots Bill Springer and Kenny Clark for safely flying us around the volcano, often in less than ideal weather, in 2008 and 2010. Any use of trade, firm, or product names is for descriptive purposes only and does not imply endorsement by the State of Alaska or U.S. Government.
(907)451-5020 (voice)
dggsgis@alaska.gov
Okmok volcano, Aleutian Islands, Alaska, explosively erupted over a five-week period between July 12 and August 23, 2008. This eruption was the first significant phreatomagmatic event in the U.S. since the Ukinrek Maars eruption in 1977. These digital data files provide field station locations and depict various geographic features described in the accompanying report.
Beget, J.E., Larsen, J.F., Neal, C.A., Nye, C.J., and Schaefer, J.R., 2005, Preliminary volcano-hazard assessment for Okmok Volcano, Umnak Island, Alaska: Report of Investigation RI 2004-3, Alaska Division of Geological & Geophysical Surveys, Fairbanks, Alaska, United States.Online Links:
Schaefer, J.R., 2005, 30-meter shaded relief image of Okmok Volcano, Umnak Island, Alaska: Raw Data File RDF 2005-1, Alaska Division of Geological & Geophysical Surveys, Fairbanks, Alaska, United States.Online Links:
Schaefer, J.R., Larsen, J.F., and Unema, J.A., 2012, Digital elevation model (DEM) and shaded relief image of Okmok Caldera, 2010: Raw Data File RDF 2011-6, Alaska Division of Geological & Geophysical Surveys, Fairbanks, Alaska, United States.Online Links:
This DGGS Report of Investigations is a final report of scientific research. It has received technical review by several scientists familiar with the subject matter. Uncertainties associated with the depiction or interpretation of various geospatial features are discussed in the manuscript.
Locations were collected by hand-held GPS units or digitized from imagery. Uncertainties associated with the location and extent of various geospatial features are discussed in the manuscript.
This is a final report of scientific research.
Not applicable
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- Access_Constraints:
- This report, map, and/or dataset is available directly from the State of Alaska, Department of Natural Resources, Division of Geological & Geophysical Surveys (see contact information below).
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RI 2015-2
The State of Alaska makes no expressed or implied warranties (including warranties for merchantability and fitness) with respect to the character, functions, or capabilities of the electronic data or products or their appropriateness for any user's purposes. In no event will the State of Alaska be liable for any incidental, indirect, special, consequential, or other damages suffered by the user or any other person or entity whether from the use of the electronic services or products or any failure thereof or otherwise. In no event will the State of Alaska's liability to the Requestor or anyone else exceed the fee paid for the electronic service or product.
DGGS publications are available as free online downloads or you may purchase paper hard-copies or digital files on CD/DVD or other digital storage media by mail, phone, fax, or email from the DGGS Fairbanks office. To purchase this or other printed reports and maps, contact DGGS by phone (907-451-5020), e-mail (dggspubs@alaska.gov), or fax (907-451-5050). Payment accepted: Cash, check, money order, VISA, or MasterCard. Turnaround time is 1-2 weeks unless special arrangements are made and an express fee is paid. Shipping charge will be the actual cost of postage and will be added to the total amount due. Contact us for the exact shipping amount.
| Data format: | Shapefile |
|---|---|
| Network links: |
<http://dx.doi.org/10.14509/29405> |
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