Grain-size data of percussion driven gravity cores collected in Alaskan lakes and fjords following the 2018 Anchorage earthquake

Frequently anticipated questions:

• What does this data set describe?
  1. How might this data set be cited?
  2. What geographic area does the data set cover?
  3. What does it look like?
  4. Does the data set describe conditions during a particular time period?
  5. What is the general form of this data set?
  6. How does the data set represent geographic features?
  7. How does the data set describe geographic features?
• Who produced the data set?
  1. Who are the originators of the data set?
  2. Who also contributed to the data set?
  3. To whom should users address questions about the data?
• Why was the data set created?
• How was the data set created?
  1. From what previous works were the data drawn?
  2. How were the data generated, processed, and modified?
  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?
  5. How consistent are the relationships among the data, including topology?
• How can someone get a copy of the data set?
  1. Are there legal restrictions on access or use of the data?
  2. Who distributes the data?
  3. What's the catalog number I need to order this data set?
  4. What legal disclaimers am I supposed to read?
  5. How can I download or order the data?
• Who wrote the metadata?

What does this data set describe?

1. How might this data set be cited?
   Singleton, Drake M., Brothers, Daniel S., Hill, Jenna C., Haeussler, Peter J., and Witter, Robert C., 20230706, Grain-size data of percussion driven gravity cores collected in Alaskan lakes and fjords following the 2018 Anchorage earthquake: data release DOI:10.5066/P924775B, U.S. Geological Survey, Pacific Coastal and Marine Science Center, Santa Cruz, California.

   Online Links:

   • https://doi.org/10.5066/P924775B

   This is part of the following larger work.
   Singleton, Drake M., Brothers, Daniel S., Hill, Jenna C., Haeussler, Peter J., and Witter, Robert C., 2023, Geophysical and core sample data collected in lakes and fjords of southcentral Alaska following the 2018 Anchorage earthquake: data release DOI:10.5066/P924775B, U.S. Geological Survey, Pacific Coastal and Marine Science Center, Santa Cruz, CA.

   Online Links:

   • https://doi.org/10.5066/P924775B

   Other_Citation_Details:

   Suggested Citation: Singleton, D.M., Brothers, D.S., Hill, J.C., Haeussler, P.J., and Witter, R.C., 2023, Geophysical and core sample data collected in lakes and fjords of southcentral Alaska following the 2018 Anchorage earthquake: U.S. Geological Survey data release, https://doi.org/10.5066/P924775B.

2. What geographic area does the data set cover?

   West_Bounding_Coordinate: -151.490850
   East_Bounding_Coordinate: -148.537050
   North_Bounding_Coordinate: 62.520180
   South_Bounding_Coordinate: 60.071108
   

3. What does it look like?
4. Does the data set describe conditions during a particular time period?

   Beginning_Date: 08-Aug-2020

   Ending_Date: 22-Jun-2021

   Currentness_Reference:

   Ground conditions at time data were collected

5. What is the general form of this data set?

   Geospatial_Data_Presentation_Form: comma-delimited text
   

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 (100)
   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 0.00001. Longitudes are given to the nearest 0.00001. Latitude and longitude values are specified in Decimal Degrees. The horizontal datum used is WGS 1984.
      The ellipsoid used is WGS 84.
      The semi-major axis of the ellipsoid used is 6378137.0.
      The flattening of the ellipsoid used is 1/298.257224.
      
7. How does the data set describe geographic features?

   2021-612_2020-625_2020-615_grainsize.csv

   Comma-delimited text file containing grain-size data for core samples. (Source: Producer defined)

   Sample ID

   Name of sample (Source: producer defined) Unique identifier for the sample used given in the laboratory

   Description

   Description of identified deposit and interpreted external trigger. For example, Sk1 2018 EQ is sampled from the Sk1 deposit from the 2018 Earthquake (EQ stands for earthquake, FL stands for flood). (Source: producer defined) Unique identifier for the sample used given in the laboratory

   Depth (mm) relative to top of core liner

   Depth of sample within core as measured from top of core liner. (Source: Producer defined)

   Range of values
   Minimum:	41
   Maximum:	308
   Units:	millimeters

   Wt. percent in -4.00 phi bin or 16 mm bin

   Weight percent of sample with grain diameter greater than -4.00 phi, or 16 mm. (Source: producer defined)

   Range of values
   Minimum:	0
   Maximum:	100
   Units:	percentage

   Wt. percent in -3.75 phi bin or 13.5 mm bin

   Weight percent of sample with grain diameter between -4.00 and -3.75 phi, or 13.5 and 16 mm. (Source: producer defined)

   Range of values
   Minimum:	0
   Maximum:	100
   Units:	percentage

   Wt. percent in -3.50 phi bin or 11.2 mm bin

   Weight percent of sample with grain diameter between -3.75 and -3.50 phi, or 11.2 and 13.5 mm. (Source: producer defined)

   Range of values
   Minimum:	0
   Maximum:	100
   Units:	percentage

   Wt. percent in -3.25 phi bin or 9.51 mm bin

   Weight percent of sample with grain diameter between -3.50 and -3.25 phi, or 9.51 and 11.2 mm. (Source: producer defined)

   Range of values
   Minimum:	0
   Maximum:	100
   Units:	percentage

   Wt. percent in -3.00 phi bin or 8 mm bin

   Weight percent of sample with grain diameter between -3.25 and -3.00 phi, or 8 and 9.51 mm. (Source: producer defined)

   Range of values
   Minimum:	0
   Maximum:	100
   Units:	percentage

   Wt. percent in -2.75 phi bin or 6.73 mm bin

   Weight percent of sample with grain diameter between -3.00 and -2.75 phi, or 6.73 and 8 mm. (Source: producer defined)

   Range of values
   Minimum:	0
   Maximum:	100
   Units:	percentage

   Wt. percent in -2.50 phi bin or 5.66 mm bin

   Weight percent of sample with grain diameter between -2.75 and -2.50 phi, or 5.66 and 6.73 mm. (Source: producer defined)

   Range of values
   Minimum:	0
   Maximum:	100
   Units:	percentage

   Wt. percent in -2.25 phi bin or 4.76 mm bin

   Weight percent of sample with grain diameter between -2.50 and -2.25 phi, or 4.76 and 5.66 mm. (Source: producer defined)

   Range of values
   Minimum:	0
   Maximum:	100
   Units:	percentage

   Wt. percent in -2.25 phi bin or 4.76 mm bin

   Weight percent of sample with grain diameter between -2.50 and -2.25 phi, or 4.76 and 5.66 mm. (Source: producer defined)

   Range of values
   Minimum:	0
   Maximum:	100
   Units:	percentage

   Wt. percent in -2.00 phi bin or 4 mm bin

   Weight percent of sample with grain diameter between -2.25 and -2.00 phi, or 4 and 4.76 mm. (Source: producer defined)

   Range of values
   Minimum:	0
   Maximum:	100
   Units:	percentage

   Wt. percent in -1.75 phi bin or 3.36 mm bin

   Weight percent of sample with grain diameter between -2.00 and -1.75 phi, or 3.36 and 4 mm. (Source: producer defined)

   Range of values
   Minimum:	0
   Maximum:	100
   Units:	percentage

   Wt. percent in -1.50 phi bin or 2.83 mm bin

   Weight percent of sample with grain diameter between -1.75 and -1.50 phi, or 2.83 and 3.36 mm. (Source: producer defined)

   Range of values
   Minimum:	0
   Maximum:	100
   Units:	percentage

   Wt. percent in -1.25 phi bin or 2.38 mm bin

   Weight percent of sample with grain diameter between -1.50 and -1.25 phi, or 2.38 and 2.83 mm. (Source: producer defined)

   Range of values
   Minimum:	0
   Maximum:	100
   Units:	percentage

   Wt. percent in -1.00 phi bin or 2 mm bin

   Weight percent of sample with grain diameter between -1.25 and -1.00 phi, or 2 and 2.38 mm. (Source: producer defined)

   Range of values
   Minimum:	0
   Maximum:	100
   Units:	percentage

   Wt. percent in -0.75 phi bin or 1.68 mm bin

   Weight percent of sample with grain diameter between -1.00 and -0.75 phi, or 1.68 and 2 mm. (Source: producer defined)

   Range of values
   Minimum:	0
   Maximum:	100
   Units:	percentage

   Wt. percent in -0.50 phi bin or 1.41 mm bin

   Weight percent of sample with grain diameter between -0.75 and -0.50 phi, or 1.41 and 1.68 mm. (Source: producer defined)

   Range of values
   Minimum:	0
   Maximum:	100
   Units:	percentage

   Wt. percent in -0.25 phi bin or 1.19 mm bin

   Weight percent of sample with grain diameter between -0.50 and -0.25 phi, or 1.19 and 1.41 mm. (Source: producer defined)

   Range of values
   Minimum:	0
   Maximum:	100
   Units:	percentage

   Wt. percent in 0.00 phi bin or 1 mm bin

   Weight percent of sample with grain diameter between -0.25 and 0.00 phi, or 1 and 1.19 mm. (Source: producer defined)

   Range of values
   Minimum:	0
   Maximum:	100
   Units:	percentage

   Wt. percent in 0.25 phi bin or 0.8409 mm bin

   Weight percent of sample with grain diameter between 0.00 and 0.25 phi, or 0.8409 and 1 mm. (Source: producer defined)

   Range of values
   Minimum:	0
   Maximum:	100
   Units:	percentage

   Wt. percent in 0.50 phi bin or 0.7071 mm bin

   Weight percent of sample with grain diameter between 0.25 and 0.50 phi, or 0.7071 and 0.8409 mm. (Source: producer defined)

   Range of values
   Minimum:	0
   Maximum:	100
   Units:	percentage

   Wt. percent in 0.75 phi bin or 0.5946 mm bin

   Weight percent of sample with grain diameter between 0.50 and 0.75 phi, or 0.5946 and 0.7071 mm. (Source: producer defined)

   Range of values
   Minimum:	0
   Maximum:	100
   Units:	percentage

   Wt. percent in 1.00 phi bin or 0.5 mm bin

   Weight percent of sample with grain diameter between 0.75 and 1.00 phi, or 0.5 and 0.5946 mm. (Source: producer defined)

   Range of values
   Minimum:	0
   Maximum:	100
   Units:	percentage

   Wt. percent in 1.25 phi bin or 0.4204 mm bin

   Weight percent of sample with grain diameter between 1.00 and 1.25 phi, or 0.4204 and 0.5 mm. (Source: producer defined)

   Range of values
   Minimum:	0
   Maximum:	100
   Units:	percentage

   Wt. percent in 1.50 phi bin or 0.3536 mm bin

   Weight percent of sample with grain diameter between 1.25 and 1.50 phi, or 0.3536 and 0.4204 mm. (Source: producer defined)

   Range of values
   Minimum:	0
   Maximum:	100
   Units:	percentage

   Wt. percent in 1.75 phi bin or 0.2973 mm bin

   Weight percent of sample with grain diameter between 1.50 and 1.75 phi, or 0.2973 and 0.3536 mm. (Source: producer defined)

   Range of values
   Minimum:	0
   Maximum:	100
   Units:	percentage

   Wt. percent in 2.00 phi bin or 0.25 mm bin

   Weight percent of sample with grain diameter between 1.75 and 2.00 phi, or 0.25 and 0.2973 mm. (Source: producer defined)

   Range of values
   Minimum:	0
   Maximum:	100
   Units:	percentage

   Wt. percent in 2.25 phi bin or 0.2102 mm bin

   Weight percent of sample with grain diameter between 2.00 and 2.25 phi, or 0.2102 and 0.25 mm. (Source: producer defined)

   Range of values
   Minimum:	0
   Maximum:	100
   Units:	percentage

   Wt. percent in 2.50 phi bin or 0.1768 mm bin

   Weight percent of sample with grain diameter between 2.25 and 2.50 phi, or 0.1768 and 0.2102 mm. (Source: producer defined)

   Range of values
   Minimum:	0
   Maximum:	100
   Units:	percentage

   Wt. percent in 2.75 phi bin or 0.1487 mm bin

   Weight percent of sample with grain diameter between 2.50 and 2.75 phi, or 0.1487 and 0.1768 mm. (Source: producer defined)

   Range of values
   Minimum:	0
   Maximum:	100
   Units:	percentage

   Wt. percent in 3.00 phi bin or 0.125 mm bin

   Weight percent of sample with grain diameter between 2.75 and 3.00 phi, or 0.125 and 0.1487 mm. (Source: producer defined)

   Range of values
   Minimum:	0
   Maximum:	100
   Units:	percentage

   Wt. percent in 3.25 phi bin or 0.1051 mm bin

   Weight percent of sample with grain diameter between 3.00 and 3.25 phi, or 0.1051 and 0.125 mm. (Source: producer defined)

   Range of values
   Minimum:	0
   Maximum:	100
   Units:	percentage

   Wt. percent in 3.50 phi bin or 0.08839 mm bin

   Weight percent of sample with grain diameter between 3.25 and 3.50 phi, or 0.08839 and 0.1051 mm. (Source: producer defined)

   Range of values
   Minimum:	0
   Maximum:	100
   Units:	percentage

   Wt. percent in 3.75 phi bin or 0.07433 mm bin

   Weight percent of sample with grain diameter between 3.50 and 3.75 phi, or 0.07433 and 0.08839 mm. (Source: producer defined)

   Range of values
   Minimum:	0
   Maximum:	100
   Units:	percentage

   Wt. percent in 3.75 phi bin or 0.07433 mm bin

   Weight percent of sample with grain diameter between 3.50 and 3.75 phi, or 0.07433 and 0.08839 mm. (Source: producer defined)

   Range of values
   Minimum:	0
   Maximum:	100
   Units:	percentage

   Wt. percent in 4.00 phi bin or 0.0625 mm bin

   Weight percent of sample with grain diameter between 3.75 and 4.00 phi, or 0.0625 and 0.07433 mm. (Source: producer defined)

   Range of values
   Minimum:	0
   Maximum:	100
   Units:	percentage

   Wt. percent in 4.25 phi bin or 0.052556 mm bin

   Weight percent of sample with grain diameter between 4.00 and 4.25 phi, or 0.052556 and 0.0625 mm. (Source: producer defined)

   Range of values
   Minimum:	0
   Maximum:	100
   Units:	percentage

   Wt. percent in 4.50 phi bin or 0.044194 mm bin

   Weight percent of sample with grain diameter between 4.25 and 4.50 phi, or 0.044194 and 0.052556 mm. (Source: producer defined)

   Range of values
   Minimum:	0
   Maximum:	100
   Units:	percentage

   Wt. percent in 4.75 phi bin or 0.037163 mm bin

   Weight percent of sample with grain diameter between 4.50 and 4.75 phi, or 0.037163 and 0.044194 mm. (Source: producer defined)

   Range of values
   Minimum:	0
   Maximum:	100
   Units:	percentage

   Wt. percent in 5.00 phi bin or 0.03125 mm bin

   Weight percent of sample with grain diameter between 4.75 and 5.00 phi, or 0.03125 and 0.037163 mm. (Source: producer defined)

   Range of values
   Minimum:	0
   Maximum:	100
   Units:	percentage

   Wt. percent in 5.25 phi bin or 0.02628 mm bin

   Weight percent of sample with grain diameter between 5.00 and 5.25 phi, or 0.02628 and 0.03125 mm. (Source: producer defined)

   Range of values
   Minimum:	0
   Maximum:	100
   Units:	percentage

   Wt. percent in 5.50 phi bin or 0.0221 mm bin

   Weight percent of sample with grain diameter between 5.25 and 5.50 phi, or 0.0221 and 0.02628 mm. (Source: producer defined)

   Range of values
   Minimum:	0
   Maximum:	100
   Units:	percentage

   Wt. percent in 5.75 phi bin or 0.01858 mm bin

   Weight percent of sample with grain diameter between 5.50 and 5.75 phi, or 0.01858 and 0.0221 mm. (Source: producer defined)

   Range of values
   Minimum:	0
   Maximum:	100
   Units:	percentage

   Wt. percent in 6.00 phi bin or 0.01563 mm bin

   Weight percent of sample with grain diameter between 5.75 and 6.00 phi, or 0.01563 and 0.01858 mm. (Source: producer defined)

   Range of values
   Minimum:	0
   Maximum:	100
   Units:	percentage

   Wt. percent in 6.25 phi bin or 0.01314 mm bin

   Weight percent of sample with grain diameter between 6.00 and 6.25 phi, or 0.01314 and 0.01563 mm. (Source: producer defined)

   Range of values
   Minimum:	0
   Maximum:	100
   Units:	percentage

   Wt. percent in 6.50 phi bin or 0.01105 mm bin

   Weight percent of sample with grain diameter between 6.25 and 6.50 phi, or 0.01105 and 0.01314 mm. (Source: producer defined)

   Range of values
   Minimum:	0
   Maximum:	100
   Units:	percentage

   Wt. percent in 6.75 phi bin or 0.00929 mm bin

   Weight percent of sample with grain diameter between 6.50 and 6.75 phi, or 0.00929 and 0.01105 mm. (Source: producer defined)

   Range of values
   Minimum:	0
   Maximum:	100
   Units:	percentage

   Wt. percent in 7.00 phi bin or 0.00781 mm bin

   Weight percent of sample with grain diameter between 6.75 and 7.00 phi, or 0.00781 and 0.00929 mm. (Source: producer defined)

   Range of values
   Minimum:	0
   Maximum:	100
   Units:	percentage

   Wt. percent in 7.25 phi bin or 0.00657 mm bin

   Weight percent of sample with grain diameter between 7.00 and 7.25 phi, or 0.00657 and 0.00781 mm. (Source: producer defined)

   Range of values
   Minimum:	0
   Maximum:	100
   Units:	percentage

   Wt. percent in 7.50 phi bin or 0.00552 mm bin

   Weight percent of sample with grain diameter between 7.25 and 7.50 phi, or 0.00552 and 0.00657 mm. (Source: producer defined)

   Range of values
   Minimum:	0
   Maximum:	100
   Units:	percentage

   Wt. percent in 7.75 phi bin or 0.00465 mm bin

   Weight percent of sample with grain diameter between 7.50 and 7.75 phi, or 0.00465 and 0.00552 mm. (Source: producer defined)

   Range of values
   Minimum:	0
   Maximum:	100
   Units:	percentage

   Wt. percent in 8.00 phi bin or 0.00391 mm bin

   Weight percent of sample with grain diameter between 7.75 and 8.00 phi, or 0.00391 and 0.00465 mm. (Source: producer defined)

   Range of values
   Minimum:	0
   Maximum:	100
   Units:	percentage

   Wt. percent in 8.25 phi bin or 0.00329 mm bin

   Weight percent of sample with grain diameter between 8.00 and 8.25 phi, or 0.00329 and 0.00391 mm. (Source: producer defined)

   Range of values
   Minimum:	0
   Maximum:	100
   Units:	percentage

   Wt. percent in 8.50 phi bin or 0.00276 mm bin

   Weight percent of sample with grain diameter between 8.25 and 8.50 phi, or 0.00276 and 0.00329 mm. (Source: producer defined)

   Range of values
   Minimum:	0
   Maximum:	100
   Units:	percentage

   Wt. percent in 8.75 phi bin or 0.00232 mm bin

   Weight percent of sample with grain diameter between 8.50 and 8.75 phi, or 0.00232 and 0.00276 mm. (Source: producer defined)

   Range of values
   Minimum:	0
   Maximum:	100
   Units:	percentage

   Wt. percent in 9.00 phi bin or 0.00195 mm bin

   Weight percent of sample with grain diameter between 8.75 and 9.00 phi, or 0.00195 and 0.00232 mm. (Source: producer defined)

   Range of values
   Minimum:	0
   Maximum:	100
   Units:	percentage

   Wt. percent in 9.25 phi bin or 0.00164 mm bin

   Weight percent of sample with grain diameter between 9.00 and 9.25 phi, or 0.00164 and 0.00195 mm. (Source: producer defined)

   Range of values
   Minimum:	0
   Maximum:	100
   Units:	percentage

   Wt. percent in 9.50 phi bin or 0.00138 mm bin

   Weight percent of sample with grain diameter between 9.25 and 9.50 phi, or 0.00138 and 0.00164 mm. (Source: producer defined)

   Range of values
   Minimum:	0
   Maximum:	100
   Units:	percentage

   Wt. percent in 9.75 phi bin or 0.00116 mm bin

   Weight percent of sample with grain diameter between 9.50 and 9.75 phi, or 0.00116 and 0.00138 mm. (Source: producer defined)

   Range of values
   Minimum:	0
   Maximum:	100
   Units:	percentage

   Wt. percent in 9.99 phi bin or 0.00098 mm bin

   Weight percent of sample with grain diameter between 9.75 and 9.99 phi, or 0.00098 and 0.00116 mm. (Source: producer defined)

   Range of values
   Minimum:	0
   Maximum:	100
   Units:	percentage

   Wt. percent in 10.25 phi bin or 0.00082 mm bin

   Weight percent of sample with grain diameter between 9.99 and 10.25 phi, or 0.00082 and 0.00098 mm. (Source: producer defined)

   Range of values
   Minimum:	0
   Maximum:	100
   Units:	percentage

   Wt. percent in 10.50 phi bin or 0.00069 mm bin

   Weight percent of sample with grain diameter between 10.25 and 10.50 phi, or 0.00069 and 0.00082 mm. (Source: producer defined)

   Range of values
   Minimum:	0
   Maximum:	100
   Units:	percentage

   Wt. percent in 10.75 phi bin or 0.00058 mm bin

   Weight percent of sample with grain diameter between 10.50 and 10.75 phi, or 0.00058 and 0.00069 mm. (Source: producer defined)

   Range of values
   Minimum:	0
   Maximum:	100
   Units:	percentage

   Wt. percent in 10.99 phi bin or 0.00049 mm bin

   Weight percent of sample with grain diameter between 10.75 and 10.99 phi, or 0.00049 and 0.00058 mm. (Source: producer defined)

   Range of values
   Minimum:	0
   Maximum:	100
   Units:	percentage

   Wt. percent in 11.25 phi bin or 0.0004 mm bin

   Weight percent of sample with grain diameter between 10.99 and 11.25 phi, or 0.0004 and 0.00049 mm. (Source: producer defined)

   Range of values
   Minimum:	0
   Maximum:	100
   Units:	percentage

   Wt. percent in 11.48 phi bin or 0.00035 mm bin

   Weight percent of sample with grain diameter between 11.25 and 11.48 phi, or 0.00035 and 0.0004 mm. (Source: producer defined)

   Range of values
   Minimum:	0
   Maximum:	100
   Units:	percentage

   Wt. percent in 12.02 phi bin or 0.000241 mm bin

   Weight percent of sample with grain diameter between 11.48 and 12.02 phi, or 0.000241 and 0.00035 mm. (Source: producer defined)

   Range of values
   Minimum:	0
   Maximum:	100
   Units:	percentage

   Wt. percent in 13.02 phi bin or 0.00012 mm bin

   Weight percent of sample with grain diameter between 12.02 and 13.02 phi, or 0.00012 and 0.000241 mm. (Source: producer defined)

   Range of values
   Minimum:	0
   Maximum:	100
   Units:	percentage

   D50 mm

   mm size at D50 for sample. (Source: producer defined)

   Range of values
   Minimum:	0.0019
   Maximum:	0.2171
   Units:	millimeters

   Entity_and_Attribute_Overview:

   The first line of the csv file is a header line. Location information for each sediment core can be found in the 2021_612_2020_625_2020_615_core_nav shapefile included in this data release.

   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)
   • Drake M. Singleton
   • Daniel S. Brothers
   • Jenna C. Hill
   • Peter J. Haeussler
   • Robert C. Witter
2. Who also contributed to the data set?
   USGS PCMSC Sediment Lab Physical Scientist Angela Tan
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?

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: 22-Jun-2021 (process 1 of 2)

   Cores were collected using a UWITEC percussion driven hammer core during U.S. Geological Survey cruises 2021-612-FA, 2020-615-FA, 2020-625-FA. The cores were transported back to the USGS Pacific Coastal and Marine Science Center core lab for subsequent analyses.

   Date: 2021 (process 2 of 2)

   The grain-size distributions of samples were determined in the USGS Pacific Coastal and Marine Science Center sediment lab. Sediment intervals of interest were sampled at 2-3mm interval (sample size ~0.5-2 grams). 10mL of deionized (DI) water was added to sample along with 2mL of a 30 percent hydrogen peroxide solution to remove organic material. Sample was then heated at 250 degrees Celsius to remove any remaining hydrogen peroxide. Afterwards 100-200mL of DI water were added and allow to settle 7 or more hours. Following settling, the sample was decanted to 10mL, followed by the addition of 1mL of 2 percent hexametaphosphate (Calgon) and sonicate for 15 minutes. The particle-size distribution was analyzed using a Beckman Coulter LS 13 320. Person who carried out this activity:
   

   Angela Tan

   U.S. Geological Survey, Pacific Coastal and Marine Science Center

   Physical Scientist

   2885 Mission Street

   Santa Cruz, CA
   

   831-460-7409 (voice)

   atan@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?
   Quality control of attribute accuracy was conducted during field data collection and processing workflows.
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?
   Dataset will be updated as additional samples are processed through the Sediment Lab at the Pacific Coastal and Marine Science Center. Users are advised to read the rest of the metadata record carefully for additional details.
5. How consistent are the relationships among the observations, including topology?
   Data received review from USGS scientist collecting and processing the data at the end of each workday.

How can someone get a copy of the data set?

1. Who distributes the data set? (Distributor 1 of 1)
   
   U.S. Geological Survey - CMGDS

   2885 Mission Street

   Santa Cruz, CA
   

   831-427-4747 (voice)

   pcmsc_data@usgs.gov
2. What's the catalog number I need to order this data set? Grain size data are provided in a comma-separated (csv) format (2021-612_2020-625_2020-615_grainsize.csv) accompanied by CSDGM FGDC-compliant metadata.
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?
   • Availability in digital form:

     Data format:	Comma-delimited text file of sediment grain-size data. in format comma-delimited text Size: 0.044
     Network links:	https://doi.org/10.5066/P924775B

   • Cost to order the data: None.

5. What hardware or software do I need in order to use the data set?
   Grain size data in .csv format can be viewed with any standard table editing software (for example, Excel, Numbers).

Who wrote the metadata?

Dates:

Last modified: 06-Jul-2023

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)