10Be - 26Al erosion rate calculator


For calculating the surface erosion rate, given that the erosion rate has been constant long enough for several meters of rock to have been removed.

Multiple sample form. Version 2.2. March, 2009. Written by Greg Balco, balcs@bgc.org

Calculators home
Exposure ages
Documentation

Enter data block here.See below for formatting instructions.


Note change in Version 2.2:
Production rates and decay constants have been updated in this version to reflect the Be-10 restandardization and half-life revision in Nishiizumi et al., 2007. Thus, you must now specify how your Be-10 and Al-26 measurements have been normalized. This means that two input fields, the Be-10 and Al-26 standardizations, have been added. You'll need to add two columns to your spreadsheets before cutting and pasting data. For a list of currently available standardizations, see this page.
Is your browser timing out before receiving the results?
It takes a few seconds to calculate each erosion rate. If the timeout setting on your browser is too short, it will stop waiting for the page before the calculations are done. You can set the wait time to a longer value on some browsers. If that's not true of yours (Safari, for example), you will have to submit fewer samples at once.
Formatting instructions:
This form is designed to have text pasted into it from a text editor or an Excel spreadsheet. The formatting requirements are unforgiving, but easy to follow once you have a spreadsheet set up appropriately. An example spreadsheet is here. The rules are as follows:
  1. Enter plain ASCII text only.
  2. Each sample should occupy its own line.
  3. Each line should have fourteen elements, as described below.
  4. Elements should be separated from each other by white space (spaces or tabs).
  5. Something other than white space must be entered for each element. For example, if you have no Al measurements for a sample, you must enter "0" in the Al concentration and Al uncertainty positions.
In most cases, pasting directly from an Excel spreadsheet should satisfy the rules. An example of an acceptable input text block appears below.

The fourteen elements are as follows:

  1. Sample name. Any text string not exceeding 24 characters. Sample names may not contain white space or any characters that could be interpreted as delimiters or escape characters, e.g., slashes of both directions, commas, quotes, colons, etc. Stick to letters, numbers, and dashes.
  2. Latitude. Decimal degrees. North latitudes are positive. South latitudes are negative.
  3. Longitude. Decimal degrees. East longitudes are positive. West longitudes are negative.
  4. Elevation/pressure. Meters or hPa, respectively, depending on selection below.
  5. Elevation/pressure flag. Specifies how to treat the elevation/pressure value. This is a three-letter text string. If you have supplied elevations in meters and the standard atmosphere is applicable at your site (locations outside Antarctica), enter "std" here. If you have supplied elevations in meters and your site is in Antarctica, enter "ant" here. If you have entered pressure in hPa, enter "pre" here. Any text other than these three options will be rejected.
  6. Sample thickness. Centimeters.
  7. Sample density. g cm-3.
  8. Shielding correction. Samples with no topographic shielding, enter 1. For shielded sites, enter a number between 0 and 1.
  9. 10Be concentration. Atoms g-1. Standard or scientific notation.
  10. Uncertainty in 10Be concentration. Atoms g-1. Standard or scientific notation.
  11. Name of Be-10 standardization. Text. Acceptable values for this parameter are given on this page.
  12. 26Al concentration. Atoms g-1. Standard or scientific notation.
  13. Uncertainty in 26Al concentration. Atoms g-1. Standard or scientific notation.
  14. Name of Al-26 standardization. Text. Acceptable values for this parameter are given on this page.
Note: Nuclide concentrations should already take account of carrier and process blanks.

Here is an example of an acceptable input text block. You can paste this in above to try a sample calculation.
     FV-TOP-1 38.6139 -109.1878 2527 std 2 2.5 1 4.59e5 1.3e4 KNSTD 2.69e6 8.80e4 KNSTD
     FV-TOP-2 38.6136 -109.1955 2580 std 2 2.5 1 202000 8000 1100000 KNSTD 49000 KNSTD
     O4-AV-PIT9-NEW -77.8282 160.9762 1300 ant 2 1.9 0.973 6710000 116000 KNSTD 0 0 KNSTD
  
Here is an Excel spreadsheet containing example data that you can paste in above to try a sample calculation.

This website is supported by the National Science Foundation via the CRONUS-Earth project