Impact of Tropical Cyclone 'Ivor' on The Great Barrier Reef, Australia

Abstract

In early March 1990 a low pressure system developed in the Coral Sea (Figure 1), which on the 17th of March, was named tropical cyclone 'Ivor'. With a barometric pressure of 965 Hpa it entered the Great Barrier Reef (GBR) Province Australia, passing over 14.9°S, 145°E and continued in a westerly direction, passing 70 km north of Lizard Island. Destructive winds were sustained at 110 km per hour and at times exceeded 180 km per hour. The Bureau of Meteorology classified 'Ivor' as a small cyclone, however, swells over 11m occurred on the outer GBR, and four metre waves were recorded in the inner reef region. 'Ivor' began to weaken on 22nd March over mainland Australia and reformed two days later to finally dissipate in the Coral Sea. This paper describes the effect of the cyclone on the living veneer of three reefs within the zone of maximum wind gusts.