Truk Atoll (Carolines, Micronesia) Site History

History Summary

Reference Level

All heights have been referred to the station tide staff zero which is linked to fixed benchmarks. Differences with PSMSL data suggest level uncertainty prior to 1963.

Tide Gauge Benchmark (TGBM) Description

Benchmark B (1948) is the primary benchmark and is stamped 'B 1948'. It is set into the concrete pavement along the north side of a row of 6 Quonset warehouses, east of the government pier.

Five additional benchmarks are levelled to the TGBM and tide station on a yearly basis.

Datum Levels

The Tide Gauge Benchmark is 8.05 feet above the Tide Gauge Zero (Station Datum). NOAA Chart Datum is 2.73 feet above Station Datum and the mean sea level (1960-1978) is 3.58 feet above Station Datum.

Quality Assessment

Comments

The daily and monthly means reveal no apparent reference level changes or trends.

The timing appears to be off by roughly 6 minutes from September - January 1992.

A datum shift of -0.65m has been corrected during the period 31/05/94(1700)-31/05/94(2300).

Notable episodic events:

• 09-10 Mar 1957: Tsunami from C. Aleutians
• 23-25 May 1960: Tsunami from S.C. Chile
• 28 Mar 1964: Tsunami from Alaska