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Your search keyword '"Rootes, Camilla M."' showing total 6 results
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6 results on '"Rootes, Camilla M."'

1. The nature and use of trimlines for analysing 3-dimensional glacier change in rugged terrain

Author

Rootes, Camilla M. and Clark, Chris D.

Subjects
550
Abstract

Reconstructions of former ice sheets and glaciers provide important palaeoglaciological information about their behaviour in response to climate changes. It is also possible to use such reconstructions to test and refine numerical glacial models, improving understanding of both palaeo and modern ice masses. The geomorphological evidence base for palaeoglacial reconstructions is often fragmentary, requiring interpolation across spatial gaps and estimation of ice thickness. These elements of subjectivity limit the robustness and reproducibility of reconstructions and this is particularly so in the rugged terrain of mountainous regions, where ice margins interact strongly with topography. This thesis aims to improve understanding of the geomorphological signature of ice margins in rugged terrain, in order to increase accuracy and confidence in producing empirical palaeoglacial reconstructions. An empirically-based method for improving interpolation between ice marginal landforms was investigated using characteristics of modern glacier-topography relationships. Despite much early promise in a pilot study, collection of sufficient data to underpin the method became too cumbersome, due to excessive measurement sensitivity in GIS analysis, and was abandoned for the purpose of this thesis. It is suggested that this avenue could be usefully continued with machine learning approaches. Glacial trimlines were then investigated because they assist both ice margin interpolation and constraint of palaeo ice thickness but have been under-utilised. A literature review on trimline characteristics and analysis of glacial trimlines in Svalbard led to a new classification scheme for their identification and interpretation, insights into controls on their formation and preservation, and examples of best practice for their mapping from remotely sensed imagery. As a proof of concept, glacial trimlines were combined with modelling to produce 3-dimensional reconstructions of the Little Ice Age geometry and volume of 15 glaciers in central western Spitsbergen, Svalbard. Glacier reduction to their modern size was found to be highly varied and related to topographic controls. The findings and recommendations of this research should be built on, in order to expand the use of glacial trimlines in palaeoglacial reconstructions and in the study of the impact of topography on glacier fluctuations.

Published
2018

2. Early Last Interglacial ocean warming drove substantial ice mass loss from Antarctica

Author

Turney, Chris S. M., Fogwill, Christopher J., Golledge, Nicholas R., McKay, Nicholas P., van Sebille, Erik, Jones, Richard T., Etheridge, David, Rubino, Mauro, Thornton, David P., Davies, Siwan M., Ramsey, Christopher Bronk, Thomas, Zoe A., Bird, Michael I., Munksgaard, Niels C., Kohno, Mika, Woodward, John, Winter, Kate, Weyrich, Laura S., Rootes, Camilla M., Millman, Helen, Albert, Paul G., Rivera, Andres, van Ommen, Tas, Curran, Mark, Moy, Andrew, Rahmstorf, Stefan, Kawamura, Kenji, Hillenbrand, Claus-Dieter, Weber, Michael E., Manning, Christina J., Young, Jennifer, and Cooper, Alan

Published
2020

5. Early Last Interglacial ocean warming drove substantial ice mass loss from Antarctica

Author

Turney, Chris S.M., Fogwill, Christopher J., Golledge, Nicholas R., McKay, Nicholas P., van Sebille, Erik, Jones, Richard T., Etheridge, David, Rubino, Mauro, Thornton, David P., Davies, Siwan M., Ramsey, Christopher Bronk, Thomas, Zoë A., Bird, Michael I., Munksgaard, Niels C., Kohno, Mika, Woodward, John, Winter, Kate, Weyrich, Laura S., Rootes, Camilla M., Millman, Helen, Albert, Paul G., Rivera, Andres, van Ommen, Tas, Curran, Mark, Moy, Andrew, Rahmstorf, Stefan, Kawamura, Kenji, Hillenbrand, Claus-Dieter, Weber, Michael E., Manning, Christina J., Young, Jennifer, Cooper, Alan, Turney, Chris S.M., Fogwill, Christopher J., Golledge, Nicholas R., McKay, Nicholas P., van Sebille, Erik, Jones, Richard T., Etheridge, David, Rubino, Mauro, Thornton, David P., Davies, Siwan M., Ramsey, Christopher Bronk, Thomas, Zoë A., Bird, Michael I., Munksgaard, Niels C., Kohno, Mika, Woodward, John, Winter, Kate, Weyrich, Laura S., Rootes, Camilla M., Millman, Helen, Albert, Paul G., Rivera, Andres, van Ommen, Tas, Curran, Mark, Moy, Andrew, Rahmstorf, Stefan, Kawamura, Kenji, Hillenbrand, Claus-Dieter, Weber, Michael E., Manning, Christina J., Young, Jennifer, and Cooper, Alan

Abstract

The future response of the Antarctic ice sheet to rising temperatures remains highly uncertain. A useful period for assessing the sensitivity of Antarctica to warming is the Last Interglacial (LIG) (129 to 116 ky), which experienced warmer polar temperatures and higher global mean sea level (GMSL) (+6 to 9 m) relative to present day. LIG sea level cannot be fully explained by Greenland Ice Sheet melt (∼2 m), ocean thermal expansion, and melting mountain glaciers (∼1 m), suggesting substantial Antarctic mass loss was initiated by warming of Southern Ocean waters, resulting from a weakening Atlantic meridional overturning circulation in response to North Atlantic surface freshening. Here, we report a blue-ice record of ice sheet and environmental change from the Weddell Sea Embayment at the periphery of the marine-based West Antarctic Ice Sheet (WAIS), which is underlain by major methane hydrate reserves. Constrained by a widespread volcanic horizon and supported by ancient microbial DNA analyses, we provide evidence for substantial mass loss across the Weddell Sea Embayment during the LIG, most likely driven by ocean warming and associated with destabilization of subglacial hydrates. Ice sheet modeling supports this interpretation and suggests that millennial-scale warming of the Southern Ocean could have triggered a multimeter rise in global sea levels. Our data indicate that Antarctica is highly vulnerable to projected increases in ocean temperatures and may drive ice–climate feedbacks that further amplify warming.

Published
2020

6. Early Last Interglacial ocean warming drove substantial ice mass loss from Antarctica

Author

Sub Physical Oceanography, Marine and Atmospheric Research, Turney, Chris S. M., Fogwill, Christopher J., Golledge, Nicholas R., McKay, Nicholas P., van Sebille, Erik, Jones, Richard T., Etheridge, David, Rubino, Mauro, Thornton, David P., Davies, Siwan M., Ramsey, Christopher Bronk, Thomas, Zoe A., Bird, Michael I., Munksgaard, Niels C., Kohno, Mika, Woodward, John, Winter, Kate, Weyrich, Laura S., Rootes, Camilla M., Millman, Helen, Albert, Paul G., Rivera, Andres, van Ommen, Tas, Curran, Mark, Moy, Andrew, Rahmstorf, Stefan, Kawamura, Kenji, Hillenbrand, Claus-Dieter, Weber, Michael E., Manning, Christina J., Young, Jennifer, Cooper, Alan, Sub Physical Oceanography, Marine and Atmospheric Research, Turney, Chris S. M., Fogwill, Christopher J., Golledge, Nicholas R., McKay, Nicholas P., van Sebille, Erik, Jones, Richard T., Etheridge, David, Rubino, Mauro, Thornton, David P., Davies, Siwan M., Ramsey, Christopher Bronk, Thomas, Zoe A., Bird, Michael I., Munksgaard, Niels C., Kohno, Mika, Woodward, John, Winter, Kate, Weyrich, Laura S., Rootes, Camilla M., Millman, Helen, Albert, Paul G., Rivera, Andres, van Ommen, Tas, Curran, Mark, Moy, Andrew, Rahmstorf, Stefan, Kawamura, Kenji, Hillenbrand, Claus-Dieter, Weber, Michael E., Manning, Christina J., Young, Jennifer, and Cooper, Alan

Published
2020

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