Data Rescue and Digitization

The Global Sea Level Observing System (GLOSS) and the International Data and Information Exchange (IODE) maintain an inventory of historic tide gauge data in non-digital form that is in need of rescue. Since 2001, this program has resulted in the extension of 91 hourly tide gauge series backwards in time for 1,411 years, and subsequently, the quality-controlled versions have been ingested into GLOSS data centers.

Despite this progress, however, vast amounts of historic data remain in paper form and sit idle in non-oceanographic facilities, such as the US National Archives and the French Prefecture Archives. The mostly paper-based tide gauge data sets are of potential great value to the sea level community for a range of applications, particularly the extension of existing sea level time series further into the past in order to understand more completely the time scales of sea level change. The goal of this endeavor is to seek support from funding agencies for rescuing tide gauge data by detailing the vast amount of known non-electronic data. Greater exposure of the inventory will be possible through the GLOSS collaboration with the Data At Risk Task Group of the Committee on Data for Science and Technology (CODATA) of the International Council for Science (ICSU).

On behalf of the GLOSS Group of Experts, we would like to ask for your support in furthering the inventory of historic, non-digital tide gauge data. If your agency/institute/facility holds historic sea level data in non-computer form, please fill out the questionnaire linked on the right side of this page. In addition, if you are aware of other facilities in your country that have such non-digital tide gauge records, we would greatly appreciate if you could provide their contact information. We are most thankful to those who have responded in the past!

Please send comments, questions, contacts for additional historic data, and/or the completed questionnaire to Mr. Patrick Caldwell, University of Hawaii Sea Level Center (UHSLC). See contact information here (bottom of page).


Example from San Francisco tide gauge

The photograph below shows one month of hourly tabulated data from San Francisco, California, May 1862. Times are in the left column, while days are listed horizontally. This photograph is is taken from a paper discussing the importance of digitizing historical sea level records by Stephen Talke and David Jay at Portland State University. The paper is freely available here.