Tidal Datum

DATA SOURCE:
National Oceanic and Atmospheric Administration (NOAA) - Historic Tide Database
NOS Station ID 9414290 San Francisco, CA

Dates 4/27/2006 - 5/24/2006

 

Established: June 30, 1854

Latitude: 37º 48.4’ N

Longitude: 122º 27.9’ W

 

Mean Range: 4.09 ft.

Diurnal Range: 5.84 ft.

 

TIDAL DATUM is a series of data sculptures visualizing tidal charts as a physical experience to reveal the subtle unseen patterns in the ocean’s sea level as the tides rise and fall in a daily and monthly cycle. The first sculpture in the series sourced tide charts recorded in San Francisco Bay from the National Oceanic and Atmospheric Administration's Online Historic Tide Database in May of 2006. The curves of the daily graphs were translated into steel, which was bent by hand, and then framed within a wood structure made from walnut.

 

The San Francisco Bay tide station is the longest continually operating tide station in the Western Hemisphere - a US Coast Survey recording tide gauge was installed on June 30, 1854. Today’s tide measurements are recorded every six minutes with electronic sensors, which are sent via satellite to NOAA headquarters, analyzed, and posted immediately to a public online database where anyone can access real-time tide data.

 

Tides are caused by the combined influences of the moon’s and sun’s gravity on the earth and its oceans. In most places on Earth, the tides go in and out every 12.42 hours, a little more than twice daily. The moon takes approximately 29 days to orbit the Earth, thus the tidal cycle repeats monthly. Tides are their most extreme during full and new moons. Twenty-nine consecutive days of observed sea level measurements were compiled and translated into a three dimensional time-series representing the daily pattern of ebb and flood tides, as well as the spring and neap tides which occur during the full and new moons respectively. These patterns can be identified by intuitively reading the forms and shapes of the steel curves in the sculpture.

 

The source data from NOAA's Historic Tide Database for the San Francisco station can be accessed here.

 

NOAA tide chart

29 tide charts layered

concept sketch  

CAD model

fabrication

DATA SOURCE:
National Oceanic and Atmospheric Administration (NOAA) - Historic Tide Database

NOS Station ID 8768094 Calcasieu Pass, LA

Dates 7/31/2011 - 8/28/2011

 

Established February 21, 1933

Latitude 29º 46.2’ N

Longitude 93º 20.6’ W

Mean Range 1.28 ft.

Diurnal Range 1.93 ft.

 

The second piece in the TIDAL DATUM series was created using tide data collected off the coast of Louisiana at Calcasieu Pass station in 2011. A site-specific, ceiling suspended version using tide data from the station in Seldovia, Alaska, was commissioned and permanently installed at the Homer Harbormaster Building Complex in 2014.

 

The source data from NOAA's Historic Tide Database for the Calcasieu Pass, LA  station can be accessed here.

 

tidal datum / Calcasieu Pass, LA

adrien segal art.design.data.sculpture © 2019 / adriensegal@gmail.com