Tidal Datum Series
TIDAL DATUM is a series of sculptures that physically reveal changing patterns in the ocean’s tides as the sea level rises and falls in a daily and monthly cycle. Twenty-nine consecutive days - one full lunar cycle - of observed sea level measurements were sourced from the NOAA’s Historic Tide Database and translated into three dimensions, capturing temporal patterns in the tide cycle as physical materials. The curves of the daily graphs were hand bent in flat bar steel, and then framed within a solid wood table.
The first in the series uses data sourced from San Francisco Bay. The series also includes versions with data collected off the coast of Louisiana and from Kachemak Bay, Alaska, which is a permanently installed public artwork suspended above the lobby of the Harbormaster Building in Homer, Alaska.
​
The source data from NOAA's Historic Tide Database for the San Francisco station can be accessed here.
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.
Tidal Datum / San Francisco Bay
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.
​
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.

Tidal Datum / Calcasieu Pass, Louisiana
NOS Station ID 8768094 Calcasieu Pass, Louisiana
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.
The source data from NOAA's Historic Tide Database for the Calcasieu Pass, LA station can be accessed here.
Tidal Datum / Kachemak Bay, Alaska
NOS Station ID 9455500 Seldovia, AK
Dates 05/01/2014 – 05/30/2014
Established May 24, 1964
Latitude 59º 26.4’ N
Longitude 151º 43.2’ W
Mean Range 15.53 ft.
Diurnal Range 18.04 ft.
Tidal Datum Kachemak Bay is a public art sculpture commissioned by the city of Homer, Alaska as part of the 1% for the Arts program. It is a suspended sculpture that hangs above the entryway to the new Harbormaster Office Complex in Homer, Alaska. The tidal range in Kachemak Bay is one of the greatest in the world - at the lowest, the water level is four feet below sea level and at its greatest is 21 feet above.
The source data from NOAA's Historic Tide Database for the Seldovia, Alaska station can be accessed here.
