Continuous Monitoring Of Seismicity By Indian Permanent Seismologicalobservatory At Maitri

摘要

Maitri, Antarctica Seismological observatory has gone global by becoming one of the permanent stations in Antarctic Seismic Web Resource (AnSWeR). The global seismic events recorded at Maitri since inception show an increasing trend of seismic activity in and around Antarctica specifically in the larger oceanic part of the Indian Plate. Some significant observations made during the XXI, XXII and XXIII Indian Antarctic Expeditions (IAE) are presented here as representative observations. The MOHO (Mohorovicic Discontinuity or often simply referred to as the "Moho") depth (an average depth of 8 kilometers beneath the ocean basin and at an average depth of about 32 kilometers beneath the continents at which seismic waves change velocity) beneath Maitri has also been estimated to be 40 km using receiver function analysis with 67 receiver functions and 108 events. The increasing seismic activity in and around Antarctica and along the oceanic ridges in the Indian Ocean confirm the emerging deforming zone in the Indian Ocean between India and Antarctica. This increased seismic activity in this region gives an insight into the spreading rates of the ridges and reorganization of plate boundaries.