Abstract
At 0255 UTC on 28 May 1989 an mb 5.8 earthquake shook the Yulara Resort and Uluru National Park in the Northern Territory of Australia. The epicenter lay 40 km west of Ayers Rock in an area where moderate-size earthquakes had not previously been recorded within 215 km. Although many people at Yulara and Uluru were alarmed, damage to buildings was minimal. The Australian National University (ANU) installed an array of 11 seismographs in the epicentral area 6 days after the mb 5.8 event. No aftershocks were detected by the ANU network during 2 weeks of recording with an estimated detection threshold of magnitude −1 to 0. Another group of seismologists who operated a single recorder near Uluru beginning 59 hours after the main shock and continuing through July, and 6 other recorders for 6 days in early June also failed to observe any aftershocks. Within the sensitivity of the arrays, the Ayers Rock event was a temporally isolated earthquake. The absence of aftershock activity is in sharp contrast to the seismicity pattern following two magnitude 5.2 earthquakes near Tennant Creek in January 1987, and to other earthquakes of magnitude 4.2 to 6.3 observed in continental intraplate settings worldwide.
