|Range of values|
|Range of values|
|Infilled lake (cutoff meander) , marsh|
|Low terrace, former tidal channel|
|marsh (freshwater) and lily pond|
|Marsh (high), or forested lowland|
|Salt and freshwater marshes|
very coarse sand => 1.000 - 2.000 mm = 0.0 to -1.0 phi coarse sand => 0.500 - 1.000 mm = 1.0 to 0.0 phi medium sand => 0.250 - 0.500 mm = 2.0 to 1.0 phi fine sand => 0.125 - 0.250 mm = 3.0 to 2.0 phi very fine sand => 0.062 - 0.125 mm = 4.0 to 3.0 phi
|Abstract||A short non- or minimally reviewed article usually prepared for a conference. Abstracts often present preliminary conclusions, give little detail, and, due to the lack of rigorous review, generally provide less dependable data.|
|Journal||An article published for the scientific community in a major journal. Journal articles are usually subject to peer review and usually provide the most dependable data.|
|Journal, field guide|
|Journal, field trip guide|
|Proceedings||Often more detailed than an abstract and published in a conference proceedings volume, may or may not be subject to peer review.|
|Thesis (M.S.)||Scientific works completed by a M.S. or Ph.D. student as part of their degree.|
|Thesis (Ph.D.)||Scientific works completed by a M.S. or Ph.D. student as part of their degree.|
|Thesis (unpublished masters project)||Scientific works completed by a M.S. or Ph.D. student as part of their degree.|
|USGS Circular||Detailed and peer-reviewed papers published by the U.S Geological Survey. When these supercede a USGS open-file report, the open file report is not included in the database.|
|USGS Professional Paper||Detailed and peer-reviewed papers published by the U.S Geological Survey. When these supercede a USGS open-file report, the open file report is not included in the database.|
The Cascadia Tsunami Deposit Database is a compilation of published data on the location and sedimentary characteristics of tsunami deposits found along the Cascadia margin. It consolidates data from the earliest published reports on Cascadia tsunami deposits (e.g. Atwater, 1987, Reinhart and Bourgeois, 1987) to studies published or in press by the year 2002. This database and associated report is intended as a guide to the sedimentary features that characterize Cascadia tsunami deposits and to the locations where tsunami deposits have been found along the Cascadia margin. It also provides references for all of the tsunami deposits cited. The Cascadia Subduction Zone (CSZ) is situated off of the Pacific Northwest coast of North America, from Northern California to Vancouver Island, British Columbia (Figure 1). Great earthquakes (m > 8.0) on subduction zones have the potential to trigger large tsunamis. While not all subduction zones generate great earthquakes, it is believed that the CSZ has the potential to generate great earthquakes. The CSZ shares many features with other subduction zones that experience great earthquakes ( Heaton and Kanamori, 1984). Geologic evidence for great earthquakes along the CSZ include turbidites off the Cascadia margin (Adams, 1990) and stratigraphic evidence of sudden coastal subsidence (e.g. Atwater et al., 1995, Nelson and Peronius, 1996). Although no great earthquakes have occurred on the CSZ since European colonization of the Pacific Northwest in the mid 1800s, an Indian oral tradition from the Pacific Northwest predating written records alludes to great shaking of the earth and coastal flooding (Heaton and Snavely, 1985, Clague, 1995). Geologic evidence for large tsunamis along the Cascadia margin has only recently been recognized. Atwater (1987) published a report attributing anomalous sand layers in marsh sediments from southern coastal Washington to tsunamis generated by great earthquakes on the CSZ. Since this time, more than 50 studies have been published, documenting numerous sites containing confirmed or potential tsunami deposits and detailing deposit characteristics along the Pacific Northwest coast from Northern California to Vancouver Island, British Columbia ( Figure 2). This rapid increase in our knowledge of Cascadia tsunami deposits has led to a greater public awareness of tsunami hazards, and improved our ability to assess the risk from future tsunamis. Data from tsunami deposits have been included on tsunami inundation maps (e.g. Walsh et al., 2000). Tsunami deposits are a key component to the recognition and mitigation of tsunami hazards in the Pacific Northwest.
Are there legal restrictions on access or use of the data?
Access_Constraints: Physical materials are under controlled on-site access.
Use_Constraints:Please recognize the U.S. Geological Survey (USGS) as the source of this information.
Physical materials are under controlled on-site access.
Some USGS information accessed through this means may be preliminary in nature and presented without the approval of the Director of the USGS. This information is provided with the understanding that it is not guaranteed to be correct or complete and conclusions drawn from such information are the responsibility of the user.
This information is not intended for navigational purposes.
Any use of trade, firm, or product names is for descriptive purposes only and does not imply endorsement by the U.S. Government.
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.
|Data format:||Tsunami deposit characteristics in format ASCII Tab-delimited Size: 0.1631|
|Data format:||Tsunami deposit characteristics in format XLS Single-sheet table in workbook format (.xls) Size: 0.2266|