SEASAT geoid anomalies and the Macquarie Ridge complex

Large Earthquakes in the Macquarie Ridge Complex: Transitional Tectonics and Subduction Initiation

-While most aspects of subduction have been extensively studied, the process of subduction initiation lacks an observational foundation. The Macquarie Ridge complex (MRC) forms the Pacific-Australia plate boundary between New Zealand to the north and the Pacific-Australia-Antarctica triple junction to the south. The MRC consists of alternating troughs and rises and is characterized by a transit...

GLOBAL GEODYNAMIC EFFECt OF THE MACQUARIE RIDGE EARTHQUAKE

Besides generating seismic waves, which eventually dissipate, an earthquake also generates a static displacement field everywhere within the Earth. This global displacement field rearranges the Earth's mass distribution, using the Earth's rotational properties and gravitational field to change. The size of these changes depends, in general, upon the size of the earthquake. The Macquarie Ridge e...

The Great MacQuarie Ridge Earthquake of 1989 Introduction

On May 23, 1989, a great earthquake struck a remote region of the South Pacific Ocean between New Zealand and Antarctica. The nearby islands are Macquarie Island, about 300 km south of the epicenter, and Campbell Island, almost 600 km east of the epicenter; the latter experienced shaking with intensity V. Fortunately, both islands are sparsely inhabited and litfie damage or injuries were report...

Anomalies in the Foundations of Ridge Regression

Teleseismic detection of a slow precursor to the great 1989 macquarie ridge earthquake.

Low-frequency spectra for the 1989 Macquarie Ridge earthquake (magnitude 8.2) show an amplitude increase and a phase-delay decrease below 6 millihertz that require a short-term slow precursor. This earthquake can be modeled as a compound event in which a fast-rupturing, ordinary earthquake was initiated by an episode of slow, smooth deformation that began more than 100 seconds before the main s...