over the West Antarctic Ice Sheet have identified

• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Subjects: Antarctic; Antarctic Peninsula; Haddington; Ross Island; West Antarctic Ice Sheet; Antarc*; Ice Sheet; James Ross Island
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.508.3553; http://pubs.usgs.gov/of/2007/1047/srp/srp060/of2007-1047srp060.pdf

Abstract James Ross Island (JRI) exposes a Miocene-Recent alkaline basaltic volcanic complex that developed in a back-arc, east of the northern Antarctic Peninsula. JRI has been the focus of several geological studies because it provides a window on Neogene magmatic processes and paleoenvironments. However, little is known about its internal structure. New airborne gravity data were collected as part of the first high-resolution aerogeophysical survey flown over the island and reveal a prominent negative Bouguer gravity anomaly over Mt Haddington. This is intriguing as basaltic volcanoes are typically associated with positive Bouguer anomalies, linked to underlying mafic intrusions. The negative Bouguer anomaly may be associated with a hitherto unrecognised low-density sub-surface body, such as a breccia-filled caldera, or a partially molten magma chamber.