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153 results on '"Hambrey, M."'

8. Secrets of a tropical ice age.

Author

Hambrey, M.

Subjects
*PLEISTOCENE stratigraphic geology
Abstract

Discusses the great Precambrian ice age which took place between 600 and 750 million years ago. How large this glaciation was; What took place in the Arctic-North Atlantic region and evidence that is found there; The atmosphere at this time. INSET: 1: Reading the rocks for signs of an ice age.;2: Making a case....

Published
1992

15. Southern Ocean bioproductivity during the last glacial cycle--new detection method and decadal-scale insight from the Scotia Sea

Author

Hambrey, M. J., Barker, P. F., Barrett, P. J., Bowman, V., Davies, B., Smellie, J. L., Tranter, M., Sprenk, Daniela, Weber, Michael E., Kuhn, Gerhard, Rosén, Peter, Molina-Kescher, Mario, Liebetrau, Volker, Röhling, Heinz-Gerd, Hambrey, M. J., Barker, P. F., Barrett, P. J., Bowman, V., Davies, B., Smellie, J. L., Tranter, M., Sprenk, Daniela, Weber, Michael E., Kuhn, Gerhard, Rosén, Peter, Molina-Kescher, Mario, Liebetrau, Volker, and Röhling, Heinz-Gerd

Abstract

We present biogenic opal flux records from two deep-sea sites in the Scotia Sea (MD07- 3133 and MD07-3134) at decadal-scale resolution, covering the last glacial cycle. In addition to conventional and time-consuming biogenic opal measuring methods, we introduce new biogenic opal estimation methods derived from sediment colour b*, wet bulk density, Si/Ti-count ratio and Fourier transform infrared spectroscopy (FTIRS). All methods capture the biogenic opal amplitude; however, FTIRS–a novel method for marine sediment – yields the most reliable results. 230Th normalization data show strong differences in sediment focusing with intensified sediment focusing during glacial times. At MD07-3134 230Th normalized biogenic opal fluxes vary between 0.2 and 2.5 g cm22 kyr21. Our biogenic opal flux records indicate bioproductivity changes in the Southern Ocean, strongly influenced by sea ice distribution and also summer sea surface temperature changes. South of the Antarctic Polar Front, lowest bioproductivity occurred during the Last Glacial Maximum when upwelling of mid-depth water was reduced and sea ice cover intensified. Around 17 ka, bioproductivity increased abruptly, corresponding to rising atmospheric CO2 and decreasing seasonal sea ice coverage

Published
2013

16. Glaciomarine sedimentation dynamics of the Abbot glacial trough of the Amundsen Sea Embayment shelf, West Antarctica

Author

Hambrey, M. J., Barker, P. F., Barrett, P. J., Bowman, V., Davies, B., Smellie, J. L., Tranter, M., Hochmuth, Katharina, Gohl, Karsten, Hambrey, M. J., Barker, P. F., Barrett, P. J., Bowman, V., Davies, B., Smellie, J. L., Tranter, M., Hochmuth, Katharina, and Gohl, Karsten

Abstract

Sedimentary sequences of the continental shelf of the eastern Amundsen Sea Embayment in West Antarctica represent records of past outlet glaciers and ice streams. The former flow of ice streams was channelled through glacial troughs, which now form large bathymetric depressions. We therefore selected one of the largest troughs, the Abbot glacial trough in the outer shelf, to analyse its glacial depositional and erosional history, based on horizon-stratigraphy derived from seismic data. Several basement highs channellized the delivery of sediment and controlled the grounded ice sheet in early glacial periods. Both pre-glacial and full glacial seismic facies were identified. Glacially transported and deposited sediments extended the shelf break by 75 km from the pre-glacial shelf-edge. The main Abbot glacial trough contains sediment from confluent ice flows of the Pine Island/Thwaites, Cosgrove and Abbot Glacier systems, as well as smaller contributions from local ice streams emanating from Thurston Island. Sherman Island of Peacock Sound played an important role in the dynamics of the Abbot Glacier by dividing the ice flow into two ice streams, which interfered with the main glacial sediment transport paths from the south. This study contributes to an understanding of the formation of the Amundsen Sea shelf and the extent of past ice sheet advances.

Published
2013

26. Origin and dynamic significance of longitudinal structures ("flow stripes") in the Antarctic Ice Sheet.

Author

Glasser, N. F., Jennings, S. J. A., Hambrey, M. J., and Hubbard, B.

Subjects
ICE sheets, SURFACE structure, REMOTE sensing, THREE-dimensional imaging in geology, PERTURBATION theory, GLACIAL erosion, GLACIAL landforms
Abstract

Longitudinal ice-surface structures in the Antarctic Ice Sheet can be traced continuously down-ice for distances of up to 1200 km. A map of the distribution of ~3600 of these features, compiled from satellite images, shows that they mirror the location of fast-flowing glaciers and ice streams that are dominated by basal sliding rates above tens of metres per annum and are strongly guided by subglacial topography. Longitudinal ice-surface structures dominate regions of converging flow, where ice flow is subject to non-coaxial strain and simple shear. They can be traced continuously through crevasse fields and through blue-ice areas, indicating that they represent the surface manifestation of a three-dimensional structure, interpreted as foliation. Flow lines are linear and undeformed for all major flow units described here in the Antarctic Ice Sheet except for the Kamb Ice Stream and the Institute and Möller Ice Stream areas, where areas of flow perturbation are evident. Parcels of ice along individual flow paths on the Lambert Glacier, Recovery Glacier, Byrd Glacier and Pine Island Glacier may reside in the glacier system for ~2500 to 18 500 years. Although it is unclear how long it takes for these features to form and decay, we infer that the major ice-flow configuration of the ice sheet may have remained largely unchanged for the last few hundred years, and possibly even longer. This conclusion has implications for our understanding of the long-term landscape evolution of Antarctica, including large-scale patterns of glacial erosion and deposition. [ABSTRACT FROM AUTHOR]

Published
2015
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31. Summary results from CRP-1, Cape Roberts Project, Antarctica

Author

Anderson, J., Armienti, P., Atkins, C., Barrett, P., Bohaty, S., Bryce, S., Claps, M., Curran, M., Davey, F.J., De Santis, L., Ehrmann, W., Florindo, F., Fielding, C., Hambrey, M., Hannah, M., Harwood, D.M., Henrys, S., Hoelscher, F., Howe, J.A., Jarrard, R., Kettler, R., Kooyman, S., Kopsch, C., Krissek, L., Lavelle, M., Levac, E., Niessen, F., Passchier, S., Paulsen, T., Powell, R., Pyne, A., Rafat, G., Raine, I.J., Roberts, A.P., Sagnotti, L., Sandroni, S., Scholz, E., Simes, J., Smellie, J., Strong, P., Tabecki, M., Talarico, F.M., Taviani, M., Verosub, K.L., Villa, G., Webb, P.N., Wilson, G.S., Wilson, T., Wise, S.W., Wonik, T., Woolfe, K., Wrenn, J.H., Anderson, J., Armienti, P., Atkins, C., Barrett, P., Bohaty, S., Bryce, S., Claps, M., Curran, M., Davey, F.J., De Santis, L., Ehrmann, W., Florindo, F., Fielding, C., Hambrey, M., Hannah, M., Harwood, D.M., Henrys, S., Hoelscher, F., Howe, J.A., Jarrard, R., Kettler, R., Kooyman, S., Kopsch, C., Krissek, L., Lavelle, M., Levac, E., Niessen, F., Passchier, S., Paulsen, T., Powell, R., Pyne, A., Rafat, G., Raine, I.J., Roberts, A.P., Sagnotti, L., Sandroni, S., Scholz, E., Simes, J., Smellie, J., Strong, P., Tabecki, M., Talarico, F.M., Taviani, M., Verosub, K.L., Villa, G., Webb, P.N., Wilson, G.S., Wilson, T., Wise, S.W., Wonik, T., Woolfe, K., and Wrenn, J.H.

Published
1998

32. Background to CRP-1, Cape Roberts Project, Antarctica

Author

Anderson, J., Armienti, P., Atkins, C., Barrett, P., Bohaty, S., Bryce, S., Claps, M., Curran, M., Davey, F.J., De Santis, L., Ehrmann, W., Florindo, F., Fielding, C., Hambrey, M., Hannah, M., Harwood, D.M., Henrys, S., Hoelscher, F., Howe, J.A., Jarrard, R., Kettler, R., Kooyman, S., Kopsch, C., Krissek, L., Lavelle, M., Levac, E., Niessen, F., Passchier, S., Paulsen, T., Powell, R., Pyne, A., Rafat, G., Raine, I.J., Roberts, A.P., Sagnotti, L., Sandroni, S., Scholz, E., Simes, J., Smellie, J., Strong, P., Tabecki, M., Talarico, F.M., Taviani, M., Verosub, K.L., Villa, G., Webb, P.N., Wilson, G.S., Wilson, T., Wise, S.W., Wonik, T., Woolfe, K., Wrenn, J.H., Anderson, J., Armienti, P., Atkins, C., Barrett, P., Bohaty, S., Bryce, S., Claps, M., Curran, M., Davey, F.J., De Santis, L., Ehrmann, W., Florindo, F., Fielding, C., Hambrey, M., Hannah, M., Harwood, D.M., Henrys, S., Hoelscher, F., Howe, J.A., Jarrard, R., Kettler, R., Kooyman, S., Kopsch, C., Krissek, L., Lavelle, M., Levac, E., Niessen, F., Passchier, S., Paulsen, T., Powell, R., Pyne, A., Rafat, G., Raine, I.J., Roberts, A.P., Sagnotti, L., Sandroni, S., Scholz, E., Simes, J., Smellie, J., Strong, P., Tabecki, M., Talarico, F.M., Taviani, M., Verosub, K.L., Villa, G., Webb, P.N., Wilson, G.S., Wilson, T., Wise, S.W., Wonik, T., Woolfe, K., and Wrenn, J.H.

Published
1998

33. Miocene strata in CRP-1, Cape Roberts Project, Antarctica

Author

Anderson, J., Armienti, P., Atkins, C., Barrett, P., Bohaty, S., Bryce, S., Claps, M., Curran, M., Davey, F.J., De Santis, L., Ehrmann, W., Florindo, F., Fielding, C., Hambrey, M., Hannah, M., Harwood, D.M., Henrys, S., Hoelscher, F., Howe, J.A., Jarrard, R., Kettler, R., Kooyman, S., Kopsch, C., Krissek, L., Lavelle, M., Levac, E., Niessen, F., Passchier, S., Paulsen, T., Powell, R., Pyne, A., Rafat, G., Raine, I.J., Roberts, A.P., Sagnotti, L., Sandroni, S., Scholz, E., Simes, J., Smellie, J., Strong, P., Tabecki, M., Talarico, F.M., Taviani, M., Verosub, K.L., Villa, G., Webb, P.N., Wilson, G.S., Wilson, T., Wise, S.W., Wonik, T., Woolfe, K., Wrenn, J.H., Anderson, J., Armienti, P., Atkins, C., Barrett, P., Bohaty, S., Bryce, S., Claps, M., Curran, M., Davey, F.J., De Santis, L., Ehrmann, W., Florindo, F., Fielding, C., Hambrey, M., Hannah, M., Harwood, D.M., Henrys, S., Hoelscher, F., Howe, J.A., Jarrard, R., Kettler, R., Kooyman, S., Kopsch, C., Krissek, L., Lavelle, M., Levac, E., Niessen, F., Passchier, S., Paulsen, T., Powell, R., Pyne, A., Rafat, G., Raine, I.J., Roberts, A.P., Sagnotti, L., Sandroni, S., Scholz, E., Simes, J., Smellie, J., Strong, P., Tabecki, M., Talarico, F.M., Taviani, M., Verosub, K.L., Villa, G., Webb, P.N., Wilson, G.S., Wilson, T., Wise, S.W., Wonik, T., Woolfe, K., and Wrenn, J.H.

Published
1998

34. Quaternary strata in CRP-1, Cape Roberts Project, Antarctica

Author

Anderson, J., Armienti, P., Atkins, C., Barrett, P., Bohaty, S., Bryce, S., Claps, M., Curran, M., Davey, F.J., De Santis, L., Ehrmann, W., Florindo, F., Fielding, C., Hambrey, M., Hannah, M., Harwood, D.M., Henrys, S., Howe, J.A., Jarrard, R., Kettler, R., Kooyman, S., Kopsch, C., Krissek, L., Lavelle, M., Levac, E., Niessen, F., Passchier, S., Paulsen, T., Powell, R., Pyne, A., Rafat, G., Raine, I.J., Roberts, A.P., Sagnotti, L., Sandroni, S., Scholz, E., Simes, J., Smellie, J., Strong, P., Tabecki, M., Talarico, F.M., Taviani, M., Verosub, K.L., Villa, G., Webb, P.N., Wilson, G.S., Wilson, T., Wise, S.W., Wonik, T., Woolfe, K., Wrenn, J.H., Anderson, J., Armienti, P., Atkins, C., Barrett, P., Bohaty, S., Bryce, S., Claps, M., Curran, M., Davey, F.J., De Santis, L., Ehrmann, W., Florindo, F., Fielding, C., Hambrey, M., Hannah, M., Harwood, D.M., Henrys, S., Howe, J.A., Jarrard, R., Kettler, R., Kooyman, S., Kopsch, C., Krissek, L., Lavelle, M., Levac, E., Niessen, F., Passchier, S., Paulsen, T., Powell, R., Pyne, A., Rafat, G., Raine, I.J., Roberts, A.P., Sagnotti, L., Sandroni, S., Scholz, E., Simes, J., Smellie, J., Strong, P., Tabecki, M., Talarico, F.M., Taviani, M., Verosub, K.L., Villa, G., Webb, P.N., Wilson, G.S., Wilson, T., Wise, S.W., Wonik, T., Woolfe, K., and Wrenn, J.H.

Published
1998

42. History of Antarctic glaciation: an Indian Ocean perspective

Author

Ehrmann, W. U., Hambrey, M. J., Baldauf, J. G., Barron, J., Larsen, B., Mackensen, Andreas, Wise, S. W. Jr., Zachos, J. C., Ehrmann, W. U., Hambrey, M. J., Baldauf, J. G., Barron, J., Larsen, B., Mackensen, Andreas, Wise, S. W. Jr., and Zachos, J. C.

Published
1992

43. Cenozoic glacial record of the Prydz Bay continental shelf, East Antarctica

Author

Hambrey, M. J., Ehrmann, W., Larsen, B., Hambrey, M. J., Ehrmann, W., and Larsen, B.

Abstract

Drilling was undertaken at five sites (739-743) on ODP Leg 119 on a transect across the continental shelf of Prydz Bay, East Antarctica, to elucidate the long-term glacial history of the area and to examine the importance of the area with respect to the development of the East Antarctic ice sheet as a whole. In addition to providing a record of glaciation spanning 36 m.y. or more, Leg 119 has provided information concerning the development of a continental margin under the prolonged influence of a major ice sheet. This has allowed the development of a sedimentary model that may be applicable not only to other parts of the Antarctic continental margin, but also to northern high-latitude continental shelves.The cored glacial sedimentary record in Prydz Bay consists of three major sequences, dominated by diamictite:1. An upper flat-lying sequence that ranges in thickness from a few meters in inner and western Prydz Bay to nearly 250 m in the outer or eastern parts of the bay. The uppermost few meters consist of Holocene diatom ooze and diatomaceous mud with a minor ice-rafted component overlying diamicton and diamictite of late Miocene to Quaternary age. The diamictite is mainly massive, but stratified varieties and minor mudstone and diatomite also occur.2. An upper prograding sequence cored at Sites 739 and 743, unconformly below the flat-lying sequence. This consists of a relatively steep (4° inclination) prograding wedge with a number of discrete sedimentary packages. At Sites 739 and 743 the sequence is dominated by massive and stratified diamictite, some of which shows evidence of slumping and minor debris flowage.3. A lower, more gently inclined, prograding sequence lies unconformably below the flat-lying sequence at Site 742 and the upper prograding sequence at Site 739. This extends to the base of both sites, to 316 and 487 mbsf, respectively.It is dominated by massive, relatively clast-poor diamictite which is kaolinite-rich, light in color, and contains spor

Published
1991

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