Crustal stress and deformation in the Earth's crust often gives rise to earthquakes. Accurate location and determination of the source mechanisms of these events is important in understanding the dynamics of plate motions. In the high latitudes, the weight of ice-sheets provides an additional force. The interaction between rock, water and ice at the base of ice-sheets is may also trigger earthquakes or make the crust more stable.

The large bodies of moving ice in the great ice-sheets also produce seismic energy. A growing field of research, glacial seismology, applies traditional seismological techniques to the understanding of the dynamics of these important regions of the Earth. In such studies, glacial seismic sources are recorded and analysed in relation to ice movement. Examples of seismic sources from glaciers are now known in Greenland and Antarctica. A study which combines GPS and seismic data is the study of Joint Seismological and Geodetic Observations on David Glacier, South Victoria Land, Antarctica

In addition to studying earthquakes/icequakes themselves, seismic data may be used in the investigation of structure at any depth within the Earth. Seismic stations in the high-latitudes are particularly important because they can (depending on the location of the source) record data which has passed through the Earth's core in a direction close to the spin axis of the Earth. The distribution of seismic stations in both the Arctic and Antarctic is relatively sparse and the legacy of new seismic stations resulting from POLENET IPY 2007-08 deployments will result in great improvements in our understanding of deep structure.

Seismic waves travel at different speeds through rocks of different composition and physical properties. If seismic stations are deployed across a region of tectonic interest, the differences in traveltime and waveform shape of the energy arriving from large, distant earthquakes may be used to determine the structure of the deployment region. An example project which uses seismic data is Variations in mantle structure beneath the TransAntarctic Mountains.

During the POLENET field deployments of the IPY 2007-2008, many new seismic stations will be deployed across key regions of the Arctic and Antarctic. Most of these stations will record data to be used in the determination of Earth structure and in the investigation of earthquakes and icequakes. Please see the field deployments page for more information on POLENET field campaigns.