Honolulu (Hawaii) Site History

History Summary

Reference Level

All heights have been referred to the station tide staff zero which is linked to fixed benchmarks. NOS performed level control on historic data (prior to 1973). An obvious level jump was adjusted by +160 mm (19Z) 26 June to (23Z) 01 July, 1953.

Tide Gauge Benchmark (TGBM) Description

Benchmark 8(1913), the primary benchmark (PBM), stamped 'BM ELV 8.06FT', is set in a concrete bulkhead on the south west side of Ala Moana Boulevard across from Hawaiian Electric Company Power Plant.

Auxilary Benchmarks

11 additional benchmarks are levelled to the TGBM and the Tide Station on a yearly basis.

Benchmark Relationships

TGBM is 12.25ft above Tide Gauge Zero (Station Datum).

NOAA Chart Datum (MLLW) is 3.69ft above Station Datum.

Mean Sea Level (1960-1978) is 4.54ft above Station Datum.

Quality Assessment

Comments

The daily and monthly means reveal no apparent reference level changes or trends and agree with the nearest stations. Anomalously high values exist within the historic data which may or may not be in error:

• 21 June and 24 June 1914
• 18-20 Febraury 1917
• 5-6 June 1917

The data for 1996-2000 were supplied with heights relative to MLLW. Consequently 1125mm was added to refer the data to tide gauge zero.

The data for 1998-2000 were supplied in non-GMT format and had to be shifted into GMT.

Notable episodic events:

• 01 April 1946: Tsunami from E. Aleutians
• 04-06 November 1952: Tsunami from Kamchatka
• 09-10 March 1957: Tsunami from C. Aleutians
• 23-25 May 1960: Tsunami from S.C. Chile
• 28 March 1964: Tsunami from Alaska
• 24 November 1982: Hurricane Iwa

Gaps in the Data Record

The following gaps occur in the data set.