For many years recordings of the beach elevation have been made. These measurements are taken at low tides and record the height of the sand at 50 foot intervals as far west as the ocean will permit - anywhere from 300 to 800 feet from the vegetation line. The data has been collected by John Markham, acting as the surveyor, with various community members drafted into service holding the measuring rod.
The data is recorded using a bolt set into steps as the reference point. This has been assigned an elevation of 50 feet, however this is just an arbitrary value, it is not a value presently linked with sea level. In addition to height measurements the horizontal distance to the edge of the rocks has been recorded.
Raw data is first recorded on paper. Images of the data as collected have been scanned as pdf files which can be found here.
There is a goal of getting data into a spreadsheet as well as csv file. That is in progress. At the moment only a small subset of the data has been digitized. Please contact firstname.lastname@example.org if you would like to work on digitization or proof reading digitized data.
Spreadsheet data for dates 2017-09-04 to 2018-09-23 as Microsoft xlsx file here.
Spreadsheet data for selected dates between 2007 and 2013 here.
The reference point is 45 degrees 48 minutes 26.9 seconds north, 123 degrees 57 minutes 54.1 seconds west. The first value in the CSV file is the horizontal distance from the reference point to the edge of the rocks, measured in feet. Remaining values are heights at 50 foot intervals relative to the reference point, also given in feet.
Measurements are taken from this set of steps on the ocean front in Arch Cape. View looking west:
Back to main Arch Cape web page.