CTD_DATABASE - Cascadia tsunami deposit database

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Frequently anticipated questions:

What does this data set describe?

Title: CTD_DATABASE - Cascadia tsunami deposit database
Abstract:
The Cascadia Tsunami Deposit Database contains data on the location and sedimentological properties of tsunami deposits found along the Cascadia margin. Data have been compiled from 52 studies, documenting 59 sites from northern California to Vancouver Island, British Columbia that contain known or potential tsunami deposits. Bibliographical references are provided for all sites included in the database. Cascadia tsunami deposits are usually seen as anomalous sand layers in coastal marsh or lake sediments. The studies cited in the database use numerous criteria based on sedimentary characteristics to distinguish tsunami deposits from sand layers deposited by other processes, such as river flooding and storm surges. Several studies cited in the database contain evidence for more than one tsunami at a site. Data categories include age, thickness, layering, grainsize, and other sedimentological characteristics of Cascadia tsunami deposits. The database documents the variability observed in tsunami deposits found along the Cascadia margin.
Supplemental_Information:
The database uses the Microsoft Excel spreadsheet program to present the data and is also available in text format (tab delimited) and as an ArcView coverage. (Some entries may be truncated in ArcView at 255 characters. Please refer to text or Excel formats for complete entries). Data categories are located on the horizontal axis (columns) and the site locations on the vertical axis (rows). Initially, the sites are sorted by latitude, from north to south, although data may be sorted by any data category in Excel by the user. The format of the data often varies from publication to publication. Wherever possible, we have used the authors own words or descriptions. Where conversions are clear and simple, we converted data into standard formats appropriate for the category, such as decimal degrees for latitude and longitude or centimeters for deposit thickness. When a publication describes more than one tsunami deposit at a site, each deposit is catalogued separately (such as, a separate row is used for each deposit). If significant differences in deposit characteristics are reported at different locations within a site, these are also catalogued separately. If an author uses one description to characterize several layers, these may be grouped into a single entry. None of the publications cited in the database cover all data categories. Many are limited in scope and cover only a few categories. In others, tsunami deposits were only a secondary theme of the paper. For some sites, there is only mention that a tsunami deposit was present, but no details are given. Expanded references for any citation in the metadata and database may be found in the reference section of the accompanying Open-File Report and on the references worksheet in the Excel spreadsheet version of the database.
  1. How might this data set be cited?
    Peters, Robert, Jaffe, Bruce, Gelfenbaum, Guy, and Peterson, Curt, 2003, CTD_DATABASE - Cascadia tsunami deposit database: Open-File Report 03-013, U.S. Geological Survey, Pacific Coastal and Marine Science Center, Santa Cruz, California.

    Online Links:

    This is part of the following larger work.

    Peters, Robert, Jaffe, Bruce, Gelfenbaum, Guy, and Peterson, Curt, 2003, Cascadia tsunami deposit database: Open-File Report 03-013, U.S. Geological Survey, Pacific Coastal and Marine Science Center, Santa Cruz, California.

    Online Links:

  2. What geographic area does the data set cover?
    West_Bounding_Coordinate: -127.8462
    East_Bounding_Coordinate: -122.7100
    North_Bounding_Coordinate: 50.5089
    South_Bounding_Coordinate: 40.6197
  3. What does it look like?
    http://geo-nsdi.er.usgs.gov/metadata/open-file/03-13/browse.png?allow=openTrue (PNG)
    ArcExplorer screen capture showing distribution of cataloged tsunami deposits from this database along with base layers showing coastlines, topography, and political boundaries, 750x554 pixels, 202k bytes
  4. Does the data set describe conditions during a particular time period?
    Beginning_Date: 1987
    Ending_Date: 2002
    Currentness_Reference:
    publication dates of compiled data
  5. What is the general form of this data set?
    Geospatial_Data_Presentation_Form: Excel, comma-delimited text, and ArcView shapefile formats
  6. How does the data set represent geographic features?
    1. How are geographic features stored in the data set?
      This is a Point data set. It contains the following vector data types (SDTS terminology):
      • Point (314)
    2. What coordinate system is used to represent geographic features?
      Horizontal positions are specified in geographic coordinates, that is, latitude and longitude. Latitudes are given to the nearest 0.0001. Longitudes are given to the nearest 0.0001. Latitude and longitude values are specified in Decimal degrees. The horizontal datum used is North American Datum of 1983.
      The ellipsoid used is Geodetic Reference System 80.
      The semi-major axis of the ellipsoid used is 6378137.000000.
      The flattening of the ellipsoid used is 1/298.257222.
  7. How does the data set describe geographic features?
    ctd_database
    Description of a tsunami deposit. Empty cells in the spreadsheet means that a particular attribute was not described in the literature. See accompanying report for details. (Source: Producer defined)
    location
    The name of the location where the tsunami deposits are located, including state/province. The name may refer to the nearest easily recognized place name, such as a town, a body of water, or other geographic feature. (Source: Producer defined) Geographical location of tsunami deposit
    catalog #
    Unique number given to an entry in this database (Source: Producer defined) Sequential identifier assigned to entry
    site #
    The site number is assigned in an ascending order based on latitude. The northernmost site in the database is assigned the number 1 and site number increases as the latitude of the site decreases. The site number of the southernmost site gives the total number of sites in the database. (Source: Producer defined) Sequential identifier assigned to entry
    core/section/secondary location
    Where individual cores at a site are listed separately, the core number is given here. If no core number is given in the publication (see "reference" attribute), a number is assigned. If the author divides a site into sections or secondary locations, their designations are given here. If no designation is given, one is assigned. (Source: Producer defined) unique descriptor
    latitude (decimal degrees)
    Latitude where the sample was collected. Latitudes and longitudes reported by the authors are used when possible (see "reference" attribute), otherwise they are measured from large-scale maps. (Source: Producer defined)
    Range of values
    Minimum:40.6197
    Maximum:50.5089
    Units:decimal degrees
    Resolution:0.0001
    longitude (decimal degrees)
    Longitude where the sample was collected. Latitudes and longitudes reported by the authors are used when possible (see "reference" attribute), otherwise they are measured from large-scale maps. (Source: Producer defined)
    Range of values
    Minimum:-122.7100
    Maximum:-127.8462
    Units:decimal degrees
    Resolution:0.0001
    depositional setting
    Depositional setting for tsunami sedimentation, such as lake, coastal marsh, freshwater marsh, etc. (Source: Producer defined) unique descriptor from the standard literature
    physiographic setting
    Additional description of sample location (Source: Producer defined) unique descriptor
    inundation distance (m)
    Inundation distance for open coastal settings is the maximum distance inland, normal to the shoreline, inundated by the tsunami. However, in other physiographic settings, the term inundation distance is subject to interpretation and the definition may change depending on the focus of the study. In a large bay or estuary, which may extend several kilometers inland from the open coast, a tsunami may propagate up a bay or even be focused by the bay. A tsunami that has a relatively small inundation distance in an open coastal setting or along a cliffed coast may travel several kilometers up a river or estuary. An inundation distance of 3 km when the site is located on a marshy riverbank does not suggest that the tsunami would inundate 3 km inland on the open coast. Therefore, when considering inundation distance, it is important to note the physiographic setting attribute in the database and reference point attribute from which inundation distance is measured. (Source: Producer defined) unique number, range of numbers, or descriptor, in meters
    inundation reference point
    Reference point from which inundation distance is measured, when known. "Open coast" means the inundation distance is measured normal to the trend of the shoreline. This usually applies to lakes and back-barrier marshes in open coastal settings. When warranted, a more specific reference may be given. "River mouth" means the distance is measured from the mouth of the river or estuary, perpendicular to the trend of the coast at the river mouth. "Up river" means the distance up a river or estuary and will not necessarily be in a strait line but will follow the course of the river. Bayshore means perpendicular to the trend of the shore within a bay. When "bayshore" is added to river descriptions it means the distance is measured from the mouth of a river that flows into a bay. Fjords are treated like open coastal settings unless specifically referred to as a river or estuary. When a more specific term is required for clarification or if the inundation reference is not clear from the authors description (see reference attribute), the authors words may be added or substituted for the above descriptions. See accompanying report for a complete description. (Source: Producer defined) unique descriptor of reference point
    elevation(mamsl)
    The present elevation of a sample location site, in meters above present mean sea level. For a paleotsunami site, both the elevation of the site and mean sea level at the time of the tsunami may have been different than at present. (Source: Producer defined) unique number, range of numbers, or descriptor, in meters above present mean sea level
    barrier elevation (mamsl)
    Elevation (modern elevation) of a barrier a tsunami must have crossed to leave a deposit at the site, in meters above mean sea level. (Source: Producer defined) unique number, range of numbers, or descriptor, in meters above present mean sea level
    Observational method/sampling method
    Method used in collecting data, such as observation from an outcrop or core, and, for cores, the type of coring device used (if specified in the citation). (Source: Producer defined) unique descriptor of method
    # cores/sampling localities
    The number of cores or sampling localities at a site. (Source: Producer defined) unique number, range of numbers, or descriptor
    # events documented (tsunami + subsidence)
    The number of subsidence events associated with great earthquakes on the CSZ, whether or not they are associated with tsunamis. Tsunamis not associated with coseismic subsidence are also included. (Source: Producer defined) unique number, range of numbers, or descriptor
    # tsunami events documented at site
    The number of tsunami events documented at a site. (Source: Producer defined) unique number, range of numbers, or descriptor
    subsidence present? (y/n or comment)
    Are the tsunami deposits associated with coseismic subsidence? (Source: Producer defined) yes, no, or other comment descriptor
    # subsidence events documented at site
    The number of subsidence events associated with great earthquakes on the CSZ that are documented at a site. (Source: Producer defined) unique number or range of numbers
    # tsunami deposits at site associated with subsidence
    The number of tsunami deposits at a site that are associated with coseismic subsidence. (Source: Producer defined) unique number
    # tsunami deposits at site not associated with subsidence
    The number of tsunami deposits at a site that are not associated with coseismic subsidence. (Source: Producer defined) unique number
    event #
    Number assigned to event at a site (tsunami or subsidence), from youngest to oldest. Numbers are site-specific and do not imply correlation with events having the same number at a different site. (Source: Producer defined) unique number, range of numbers, or other descriptor
    tsunami event #
    Number assigned to tsunami deposit at a site, from youngest to oldest. (Source: Producer defined) unique number, range of numbers, or other descriptor
    subsidence event #
    The number assigned to subsidence event at a site, from youngest to oldest. (Source: Producer defined) unique number
    amount of subsidence (m)
    The amount of coseismic subsidence reported, in meters. (Source: Producer defined) unique number, range of numbers, or other descriptor
    age (rcybp)
    Age of deposit in radiocarbon years before present. Ages reported are those of the authors (see reference attribute) and are usually reported relative to 1950. Ages reported in rcybp need to be calibrated before they can accurately represent the age of the deposit (see accompany report for further details). (Source: Producer defined) unique number or range of numbers
    age range (cybp)
    The range of possible ages in calendar years before present. See accompanying report for further details. (Source: Producer defined) unique number or range of numbers
    correlated date (in years A.D. unless otherwise noted)
    If the deposit is correlated by the author (see reference attribute) to a known or accepted event, the correlated date is given here. Ages are given in years A.D. unless otherwise noted. (Source: Producer defined) unique number, range of numbers, or other descriptor
    age method/comments
    Method used to determine the age of the deposits. The age reported represents a maximum age for the deposits. See accompanying report for details. (Source: Producer defined) unique descriptor
    thickness (cm)
    The reported thickness of the tsunami deposit, in centimeters, inclusive of all layers present. Thickness is not constant in tsunami deposits. Thinning of the deposit landward and away from channels often characterizes tsunami deposits. Different authors (see reference attribute) report thickness in different ways. Sometimes thickness is reported as an average thickness or representative thickness, other times only a local thickness is reported. Other times a range of thicknesses is reported. (Source: Producer defined) unique number, range of numbers, or other descriptor
    maximum thickness (cm)
    If a maximum thickness is reported independent of the average, representative, or range of thicknesses, it is reported here in centimeters. (Source: Producer defined) unique number or other descriptor
    geometry
    Description of gradients in thickness (landward thinning, etc.) and continuity of the deposit. (Source: Producer defined) unique descriptor
    thickness (cm)
    The reported thickness of the tsunami deposit, in centimeters, inclusive of all layers present. Thickness is not constant in tsunami deposits. Thinning of the deposit landward and away from channels often characterizes tsunami deposits. Different authors (see reference attribute) report thickness in different ways. Sometimes thickness is reported as an average thickness or representative thickness, other times only a local thickness is reported. Other times a range of thicknesses is reported. (Source: Producer defined) unique number, range of numbers, or other descriptor
    maximum thickness (cm)
    If a maximum thickness is reported independent of the average, representative, or range of thicknesses, it is reported here in centimeters. (Source: Producer defined) unique number or other descriptor
    # layers
    The number of layers in a tsunami deposit (for example, sand-mud couplets, heavy mineral layers, organic horizons, etc.). See accompanying report for details. (Source: Producer defined) unique number, range of numbers, or other descriptor
    layer thickness (cm)
    Thickness of individual layers, in centimeters (Source: Producer defined) unique descriptor
    layer characteristics
    Specific characteristics of individual tsunami layers (Source: Producer defined) unique descriptor
    underlying material
    Description of the material underlying the deposit. (Source: Producer defined) unique descriptor
    overlying material
    Description of the material overlying the deposit. (Source: Producer defined) unique descriptor
    lower contact
    Description of the lower contact bounding the tsunami deposit. See accompanying report for details. (Source: Producer defined) unique descriptor
    upper contact
    Description of the upper contact bounding the tsunami deposit. See accompanying report for details. (Source: Producer defined) unique descriptor
    grain size range(phi)
    The size range of sand grains found in the deposit, in units of phi. See accompanying report for details of size range breakdowns. (Source: Producer defined) unique range of numbers
    grain size distribution
    The distribution of grain sizes within a deposit. (Source: Producer defined) unique descriptor
    grain size description
    Description of grain size within a deposit. The authors original words are given here whenever possible (see reference attribute). (Source: Producer defined) unique descriptor
    horizontal textural gradient
    Description of grain size changes in the horizontal direction. See accompanying report for details. (Source: Producer defined) unique descriptor
    grading
    Description of textural changes in the vertical direction within a layer. See accompanying report for details. (Source: Producer defined) unique descriptor
    sorting
    Describes a measure of the variability of the grain sizes in the deposit. See the accompanying report for details. (Source: Producer defined) unique descriptor
    other sedimentary structures or properties
    Miscellaneous sedimentary properties that characterize the deposit or grains within the deposit. The authors original words are given here whenever possible. (Source: Producer defined) unique descriptor
    compositon
    Mineralogical composition of the sediment grains in the deposit. See accompanying report for details. (Source: Producer defined) unique descriptor
    inclusions
    Material other than sediment grains in a deposit. (Source: Producer defined) unique descriptor
    flow direction
    The direction of flow as indicated by the deposit. See accompanying report for details. (Source: Producer defined) unique descriptor
    microfossils
    Description of any microfossils found in the deposit. See accompanying report for details. (Source: Producer defined) unique descriptor
    chemical evidence
    Describes any chemical evidence that the deposit is from a tsunami. (Source: Producer defined) unique descriptor
    comments/additional descriptions
    Other information pertaining to the tsunami deposits, site, or publication that does not fit into the other categories is reported here. (Source: Producer defined) unique descriptor
    reference
    Citing for reference that provided the data, by author and year. Complete citing is listed in the reference section of the accompanying report and on the references worksheet of the database. (Source: Producer defined) unique descriptor
    reference type
    Publication type of reference. See accompanying report for more details. (Source: Producer defined) unique descriptor
    reference date
    Date of reference publication. (Source: Producer defined) unique descriptor
    map (USGS 7.5 minute quadrangle for U. S., NTS 1:50,000 for Canada)
    Reference map covering location of site. USGS 7.5 minute quadrangles are used for locations in the United States. National Topographic System (NTS) 1:50,000 maps published by Energy, Mines and Resources, Canada are used for locations in Canada. (Source: Producer defined) unique descriptor
    Entity_and_Attribute_Overview: The first line of the database file is a header line.
    Entity_and_Attribute_Detail_Citation: U.S. Geological Survey

Who produced the data set?

  1. Who are the originators of the data set? (may include formal authors, digital compilers, and editors)
    • Robert Peters
    • Bruce Jaffe
    • Guy Gelfenbaum
    • Curt Peterson
  2. Who also contributed to the data set?
  3. To whom should users address questions about the data?
    U.S. Geological Survey, Pacific Coastal and Marine Science Center
    Attn: PCMSC Science Data Coordinator
    2885 Mission Street
    Santa Cruz, CA

    831-427-4747 (voice)
    pcmsc_data@usgs.gov

Why was the data set created?

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 (for example, 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 (see Figure 1 in the accompanying Open-File Report). Great earthquakes (magnitude greater than 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 (for example, Atwater and others, 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 (see Figure 2 in accompanying Open-File Report). 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 (for example, Walsh and others, 2000). Tsunami deposits are a key component to the recognition and mitigation of tsunami hazards in the Pacific Northwest.

How was the data set created?

  1. From what previous works were the data drawn?
  2. How were the data generated, processed, and modified?
    Date: 2003 (process 1 of 4)
    Identification of CSZ Tsunami Deposits
    The studies cited in the database use a variety of sedimentary features to identify tsunami deposits in outcrops and cores. Preliminary identification of tsunami deposits is often based on the recognition of anomalous layers of sand in environments where the deposition of sand layers is unusual, such as coastal marshes or lakes (Reinhart and Bourgeois, 1987). Tsunamis can transport sand, cobbles, boulders and debris from offshore and from beaches and deposit it over coastal lowlands (Dawson, 1994). However, other energetic processes, such as river flooding or storm surges, may leave sandy deposits in otherwise low-energy environments (Nelson and others, 1996). Key sedimentary characteristics of the deposit are often cited to confirm a tsunami origin for the sand layer. While no single characteristic may universally be used to distinguish a tsunami deposit, the combination of several characteristics are often used to rule out other processes and leave little or no doubt as to a tsunami origin for the deposit. Tsunami deposits may be distinguished from river deposits by distinct biological markers, spatial distribution, sediment characteristics and geochemistry. The presence of marine or brackish water macro- and microfossils is used to infer a marine rather than river source for the deposit (Hemphill- Haley, 1995). Thinning and fining of the deposit landward are often used to suggest a marine surge rather than a river source for the deposit (Atwater, 1987; Benson and others, 1997). Flop-overs, which consist of the leaves and stems of herbaceous plants bent over by the flow, preserve information about flow direction and may indicate a landward-directed flow, suggesting a marine source (Atwater and Hemphill-Haley, 1997). The composition and texture of the sand grains has been used to differentiate between a coastal or upriver source (Darienzo and Peterson, 1990; Peterson and Darienzo, 1996). Geochemical indicators, such as bromine enrichment, have also been used to indicate a marine source for the deposit (Schlichting, 2000). Storm surge deposits are more difficult to distinguish from tsunami deposits because, similar to tsunami deposits, they also contain marine or brackish water macro- and microfossils, have saltwater chemistry, and thin and fine landward (Nelson and others, 1996). Some studies use distance inland to indicate a tsunami source, arguing that it is not likely that storm waves or a storm surge could deposit sand inland to the extent of the deposit (Clague and others, 2000). Reinhart (1991) argues that in protected tidal channels, storms are unlikely to suspend the volume of sediment necessary to produce the deposits observed. When layers are present, their number and thickness are sometimes used to differentiate between a tsunami and storm deposit (Williams and Hutchinson, 2000, Witter, in press). Tsunami deposits tend to have several relatively thick normally graded beds, suggesting deposition from suspension by successive waves in the tsunami wave train, while storm deposits may be expected to have thinner and more numerous laminations from higher frequency but lower energy storm waves (Nelson and others, 1996b). Abramson (1998) uses the presence of rip-up clasts in the deposit to indicate the higher energy deposition of a tsunami. Association of the sand layer with paleoseismicity is often used to link a sand layer to a tsunami source. Coseismic coastal subsidence may accompany great subduction zone earthquakes (Atwater, 1996). Association of the sand layer with evidence of coseismic subsidence is often key to the identification of the sand layer as a tsunami deposit (Atwater, 1987, Darienzo and Peterson, 1990). This is usually seen as a buried soil or layer of peat, representing a marsh surface that formed above the reach of high tide, abruptly overlain by a layer of sand (the tsunami deposit), which is then overlain by tidal flat mud. Linking a sand layer to liquifaction features also may tie a potential tsunami deposit to a seismic event (Atwater, 1992). The presence of stems of herbaceous plants in growth position within the deposit is used to indicate approximate coincidence of deposition of the sand layer with submergence of the marsh surface (Atwater, 1992). Deposit geometry and the number of sand layers present in a core or outcrop are sometimes used to differentiate between a deposit produced by a tsunami from a great earthquake on the CSZ and one left by a tsunami with a distant source. Carver and others (1996) proposed using deposit extent and thickness to differentiate CSZ tsunamis from distant tsunamis by comparing them to deposits left by historic distant tsunamis. Witter (2001) uses the estimated 500-540 year average recurrence interval for great CSZ earthquakes (Atwater and Hemphill Haley, 1997) to suggest that at least two out of four sand layers in a 600 year interval were deposited by distant tsunamis or storm surges. In lake deposits, the source of the tsunami (local or distant) may not be evident in the sediments (Clague, 1997).
    Date: 2003 (process 2 of 4)
    Metadata imported.
    Date: 22-Nov-2019 (process 3 of 4)
    Edits were made to the metadata to bring it up to current standards and syntax. Keywords were refined and added to assist in data discovery to comply with current USGS open-access policies. No data were changed. Person who carried out this activity:
    Susan A Cochran
    U.S. Geological Survey, Pacific Coastal and Marine Science Center
    2885 Mission St.
    Santa Cruz, CA
    United States

    831-460-7545 (voice)
    scochran@usgs.gov
    Date: 19-Oct-2020 (process 4 of 4)
    Edited metadata to add keywords section with USGS persistent identifier as theme keyword. No data were changed. Person who carried out this activity:
    U.S. Geological Survey
    Attn: VeeAnn A. Cross
    Marine Geologist
    384 Woods Hole Road
    Woods Hole, MA

    508-548-8700 x2251 (voice)
    508-457-2310 (FAX)
    vatnipp@usgs.gov
  3. What similar or related data should the user be aware of?

How reliable are the data; what problems remain in the data set?

  1. How well have the observations been checked?
  2. How accurate are the geographic locations?
  3. How accurate are the heights or depths?
  4. Where are the gaps in the data? What is missing?
    It is the goal of the authors that the database be comprehensive. The database currently cites 53 papers documenting 60 sites where known or potential tsunami deposits have been reported along the Cascadia margin (see Figure 2 in the accompanying report). All known journal articles pertaining to specific sites along the Cascadia margin and published in English by the time of submission have been included. While every attempt has been made to include all theses and conference or symposium abstracts and proceedings that pertain to Cascadia tsunami deposits, the limited availability and inadequate referencing of some of these publications has made some omissions likely. Also, some conference abstracts that were superceded by journal publications were omitted if they did not contain any additional information. Similarly, if a USGS open file report was superceded by a USGS professional paper, only the professional paper was included. The Cascadia Tsunami Deposit Database documents the variety found in tsunami deposits along the Pacific Northwest coast. It contains data on the age, number of deposits, sedimentary characteristics and identifying features of Cascadia tsunami deposits. It includes data from Northern California, north of the Mendocino triple junction through Vancouver Island, British Columbia, Canada. While the focus of the database are deposits from tsunamis that originate from earthquakes on the CSZ, data from historical tsunami deposits originating from trans-oceanic tsunamis are included for comparison. Tsunami deposits located in the Puget Sound area that are not believed to be of a Cascadia origin are not included in the database.
  5. How consistent are the relationships among the observations, including topology?
    The data derive from a wide variety of studies with differences in focus, scope, and intent. Details concerning techniques, errors, difficulties, inconsistencies, variability, and potential alternate interpretations of the data are beyond the scope of this report. These are usually site-specific and the original citation should be consulted. This report contains data from both peer-reviewed journals and from publications not typically subjected to extensive peer review. Techniques varied widely among the various studies and the accuracy and precision between separate entries may not be comparable. No attempt has been made in this report to quantify errors. The exception is in dating the deposits, where the errors reported in the publications are included. Even these may not be comparable due to differences in material dated, sampling techniques, or in the case of ages reported in calendar years, the calibration curve used and the error estimation method (Stuvier and Becker, 1986, 1993). It is recommended that the original reference, supplied for each entry, be consulted before using data compiled in this report.

How can someone get a copy of the data set?

Are there legal restrictions on access or use of the data?
Access_Constraints: None.
Use_Constraints:
USGS-authored or produced data and information are in the public domain from the U.S. Government and are freely redistributable with proper metadata and source attribution. Please recognize and acknowledge the U.S. Geological Survey as the originator(s) of the dataset and in products derived from these data.
  1. Who distributes the data set? (Distributor 1 of 1)
    Guy Gelfenbaum
    U.S Geological Survey
    Oceanographer
    2885 Mission St.
    Santa Cruz, CA
    USA

    (831) 460-7401 (voice)
    ggelfenbaum@usgs.gov
  2. What's the catalog number I need to order this data set? Downloadable Data: USGS Open-File Report 03-13; Cascadia tsunami deposits database (ctd_database)
  3. What legal disclaimers am I supposed to read?
    Unless otherwise stated, all data, metadata and related materials are considered to satisfy the quality standards relative to the purpose for which the data were collected. Although these data and associated metadata have been reviewed for accuracy and completeness and approved for release by the U.S. Geological Survey (USGS), no warranty expressed or implied is made regarding the display or utility of the data on any other system or for general or scientific purposes, nor shall the act of distribution constitute any such warranty.
  4. How can I download or order the data?
  5. What hardware or software do I need in order to use the data set?
    These data are available in Environmental Systems Research Institute (ESRI) shapefile format. The user must have ArcGIS or ArcView 3.0 or greater software to read and process the data file. In lieu of ArcView or ArcGIS, the user may utilize another GIS application package capable of importing data. A free data viewer, ArcExplorer, capable of displaying the data is available from ESRI at www.esri.com.

Who wrote the metadata?

Dates:
Last modified: 19-Oct-2020
Metadata author:
U.S. Geological Survey, Pacific Coastal and Marine Science Center
Attn: PCMSC Science Data Coordinator
2885 Mission Street
Santa Cruz, CA

831-427-4747 (voice)
pcmsc_data@usgs.gov
Metadata standard:
Content Standard for Digital Geospatial Metadata (FGDC-STD-001-1998)
This page is <https://cmgds.marine.usgs.gov/catalog/pcmsc/SeriesReports/OFR/OFR_03-013/ctd_database.faq.html>
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