Earthquakes occur in Antarctica. The previously held notion that Antarctica is essentially aseismic has been disproved by using records from established Global Seismic Network stations and recently deployed temporary stations on the Antarctic continent. However, the seismicity observed in Antarctica is very low in comparison with other continental intraplate regions. This contribution critically reviews magnitude threshold levels for recorded earthquakes and the available earthquake hypo-center data for Antarctica and the surrounding oceans. Patterns are identified in the distribution of Antarctic earthquakes and the deformation of the Antarctic plate, and the interplay between tectonic and ice-related forces controlling this distribution is discussed. In the continental intraplate region of Antarctica, earthquakes occur in three settings. Two are likely to have distributions with a tectonic control (although the level may be suppressed by ice cover)—those in the Transantarctic Mountains and scattered events in the interior. Finally, seismicity in the coastal zone and continental margin is likely to be most strongly controlled by the interaction between glacial isostatic adjustment and lithospheric thickness, with a regional tectonic component in some locations.

Abstract The crust and upper mantle structure beneath a single, three-component broadband seismic station may be determined using energy from distant earthquakes. Features such as the depth of the seismic Moho, the abruptness of the change in seismic velocity across the Moho, the velocity profile through the crust and the seismic velocity of the upper mantle may be found using receiver function techniques. Waveforms are analysed which contain energy arising from the interaction of incoming signals with the Earth structure beneath the receiving station. Seismic characteristics of the deep crust are often continuous or slowly varying across a single terrane and, moreover, show sudden contrasts across terrane and other major tectonic boundaries. Such techniques are, therefore, appropriate tools in the exploration of deep structure and, hence, in the understanding of large-scale continental assembly. They complement geological and geochronological investigations of surface rocks by providing the third spatial dimension. In regions of no surface basement exposure, seismic and other geophysical methods provide the only means of mapping the lateral extent of a given terrane and/or tracing province boundaries. Receiver function methods are presented here in the context of terrane tectonics with illustrative examples from former Gondwanan provinces and locations on the Pacific margin.