Abstract
AbstractGround-penetrating radar (GPR) is becoming a commonly applied technique in geomorphology. However, its use in the study of subglacial bedforms has yet to be fully explored and exploited. This paper presents the results of a GPR feasibility study conducted on a drumlinized terrain in Cumbria, UK, where five drumlins were investigated using multiple radar antenna frequencies. The site was selected for the presence of nearby bedrock outcrops, suggesting a shallow drumlinized diamict–bedrock contact and a permeable lithology. Despite the clayey sediment and unfavourable weather conditions, a considerable penetration depth of ~12 m was achieved when using a 50 MHz antenna, with a separation of 1 m, trace spacing of 1 m and 128-fold vertical stack. Results indicate that the drumlinized diamict is in direct erosional contact with the bedrock. While the internal drumlin geometry is generally chaotic on the stoss side, evidence of layering dipping downflow at an angle greater than the drumlin surface profile was found on the lee side. The inter-drumlin areas comprise ~4 m of infill sediment that masks part of the original drumlin profile. Overall, this study indicates that GPR can be deployed successfully in the study of glacial bedform sedimentary architecture.
Highlights
Terrain formerly covered by an ice sheet is often characterized by the widespread presence of subglacial landforms.The most common of these landforms is the drumlin, an oval-shaped hill with a relatively symmetrical profile, an average width of 200 m, a length of 600 m and a relief of 7 m (Clark and others, 2009; Spagnolo and others, 2010, 2011, 2012)
The topic is significant because drumlins are formed at the ice–bed interface, which plays a major role in the dynamics of ice sheets and likely modulates their response to climate forcing (e.g. Kleman and Glasser, 2007)
The remaining seven profiles were of poorer quality, either because the acquisition parameters were not ideal, or they were heavily impacted by the presence of nearby walls and roads, and by perched water tables
Summary
Terrain formerly covered by an ice sheet is often characterized by the widespread presence of subglacial landforms. The most common of these landforms is the drumlin, an oval-shaped hill with a relatively symmetrical profile, an average width of 200 m, a length of 600 m and a relief of 7 m (Clark and others, 2009; Spagnolo and others, 2010, 2011, 2012). Boulton and Clark, 1990). Despite their widespread presence and a history of research dating back three centuries (Menzies, 1984), drumlins remain among the most enigmatic landforms on Earth, with many, sometimes opposing, formation theories having been formulated and in many instances still being debated The topic is significant because drumlins are formed at the ice–bed interface, which plays a major role in the dynamics of ice sheets and likely modulates their response to climate forcing The topic is significant because drumlins are formed at the ice–bed interface, which plays a major role in the dynamics of ice sheets and likely modulates their response to climate forcing (e.g. Kleman and Glasser, 2007)
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
