A 100 Year Record of Ocean Temperature Control on the Stability of Jakobshavn Isbrae, West Greenland
Lloyd, J.M., Moros, M., Perner, K., Telford, R., Kuijpers, A., Jansen, E., McCarthy, D. 2011. A 100 year record of ocean temperature control on the stability of Jakobshavn Isbrae, West Greenland. Geology. 39, 867-870, doi: 10.1130/G32076.1.
- This study demonstrates the influence of ocean circulation on the dynamics of Jakobshavns Isbrae, a major icestream draining the Greenland Ice Sheet
- Reconstructed the variations in the relative warmth of the West Greenland Current over the past 100 years based on benthic foraminifera
- Identified the recent ocean warming based on instrumental measurements from the late 1990s in the benthic foraminifera fauna that has been linked to break up and retreat of the Jakobshavns Isbrae calving margin
- Identified an earlier period of ocean warming from 1920s to 1950s that corresponds to an earlier period of retreat of the calving margin of Jakobshavns Isbrae based on historical observations
A New Glacial Isostatic Adjustment Model for Antarctica: Calibrated and Tested Uusing Observations of Relative Sea Level Change and Present-day Uplift Rates
Whitehouse, P.L., Bentley, M.J., Milne, G.A., King, M.A. & Thomas, I.D. A new glacial isostatic adjustment model for Antarctica: calibrated and tested using observations of relative sea level change and present-day uplift rates. Geophysical Journal International. 2012;190:1464-1482.
- Glacial Isostatic Adjustment (GIA) model for Antarctica
- First Antarctic GIA model to be specifically driven using ice sheet model output
- First model to account for uncertainty associated with both ice sheet history and Earth rheology
- Tuned using continent-wide GPS data
A Systematic Review of Geological Evidence for Holocene Earthquakes and Tsunamis Along the Nankai-Suruga Trough, Japan
Garrett E, Fujiwara O, Garrett P, et al. (2016). A systematic review of geological evidence for Holocene earthquakes and tsunamis along the Nankai-Suruga Trough, Japan. Earth-Science Reviews. 159: 337-357.
- First comprehensive review of geological evidence for past earthquakes and tsunamis along the Nankai-Suruga megathrust, incorporating both English and Japanese language publications
- Rupture zones of 12 great (magnitude >8) earthquakes mapped
- Intervals between ruptures of discrete regions range from <100 to >450 years
- Largest ruptures occurred in 684, 1361 and 1707 CE, with no geological evidence currently available for larger prehistoric earthquakes or tsunamis
An Extensive and Dynamic Ice Sheet on the West Greenland Shelf During the Last Glacial Cycle
Ó Cofaigh, C., Dowdeswell, J.A., Jennings, A.E., Hogan, K., Kilfeather, A., Hiemstra, J.F., Noormets, R., Evans, J., McCarthy, D.J., Andrews, J.T., Lloyd, J.M. and Moros, M. (2013). An extensive and dynamic ice sheet on the West Greenland shelf during the last glacial cycle. Geology, v. 41, p. 219-222.
- Marine geological and geophysical investigation of Greenland Ice Sheet history on the continental shelf offshore central west Greenland
- Shelf-edge terminating ice sheet at the LGM with grounded ice streams flowing to continental shelf edge through bathymetric troughs
- First dates on timing of ice sheet retreat from outer shelf indicating that ice sheet retreat was underway by at least 14.9kyr BP
- Rapid readvance of ancestral Jakobshavn Isbræ ice stream to the outer shelf during the Younger Dryas stadial
An Extensive Subglacial Lake and Canyon System in Princess Elizabeth Land, East Antarctica
Jamieson, S.S.R., Ross, N., Greenbaum, J.S., Young, D.A., Aitken, A.R.A., Roberts, J.L., Blankenship, D.D., Sun, B. & Siegert, M.J. An extensive subglacial lake and canyon system in Princess Elizabeth Land, East Antarctica. Geology. 2016;44:87-90.
- The landscape beneath the ice in Princess Elizabeth Land, East Antarctica, is one of the last places on Earth to remain unmapped
- Using satellite imagery, we identified the possible presence of a very large subglacial lake
- We suggested the existence of a series of massive channels over 1000km long, possibly linked to the lake
- Understanding these features will provide insight into the geological and glaciological history of Antarctica
Chronological Variations in Handaxes: Patterns Detected from Fluvial Archives in North-west Europe
Bridgland, D.R. & White, M.J. (2015) Chronological variations in handaxes: patterns detected from fluvial archives in north-west Europe. Journal of Quaternary Science. 30, 623-638.
- Shows that handaxe types, artefacts representing pre-Homo sapiens occupation of NW Europe, have geochronological significance
- This has been established largely from the well-dated record from the Thames terraces (see illustration, next slide)
- Ongoing investigation of the extent of this pattern into continental Europe
Handbook of Sea Level Research
Shennan, I.S., Long, A.J. and Horton, B.P. (2017) Handbook of Sea Level Research. Wiley.
- Aims to provide a practical guide, from the initial design of research approaches through to the practical issues of data collection and interpretation from a diverse range of coastal environments
- Builds on thirty years of international research, with 38 chapters authored by leading experts from around the world
- Important resource for those wanting to learn more about sea level change:
- scientists interested and involved in understanding sea level changes across a broad range of disciplines
- policy makers wanting to appreciate our current state of knowledge of sea level change over different timescales
- teachers at the university level
- advanced-level undergraduates and postgraduate research students
Ice Stream Activity Scaled to Ice Sheet Volume During Laurentide Ice Sheet deglaciation
Stokes, C.R., Margold, M., Clark, C.D. and Tarasov, L. (2016). Ice stream activity scaled to ice sheet volume during Laurentide Ice Sheet deglaciation. Nature. 530, 322-326.
- The behaviour of ice streams is one of the largest sources of uncertainty when predicting the response of ice sheets to future climate change
- Here we reconstruct the activity of 117 ice streams that operated at various times during deglaciation of the Laurentide Ice Sheet from about 22,000 to 7,000 years ago
- We show that as they activated and deactivated in different locations, their overall number decreased, they occupied a progressively smaller percentage of the ice sheet perimeter and their total discharge decreased
- Contrary to the view that sees ice streams as unstable entities that can accelerate ice sheet deglaciation, we conclude that ice streams exerted progressively less influence on ice sheet mass balance during the retreat of the Laurentide Ice Sheet
New Constraints on Late Holocene Eustatic Sea Level Changes from Mahé, Seychelles
Woodroffe, S.A., Long, A.J., Milne, G.A., Bryant, C.L. & Thomas, A. 2015. New constraints on late Holocene eustatic sea level changes from Mahé, Seychelles. Quaternary Science Reviews. 115:1-16.
- New estimates of globally integrated ice sheet melt during the late Holocene from Seychelles
- Mangrove sediments suggest relative sea level was between -2m and present in the last 2ka
- We correct sea level data for Glacial-isostatic adjustment using ICE-5G and EUST3
- The global eustatic contribution during the last 2ka has been less than 2m
Ocean Forcing of Glacier Retreat in the Western Antarctic Peninsula
Cook, A.J., Holland, P.R., Meredith, M.P., Murray, T., Luckman, A. & Vaughan, D.G. Ocean forcing of glacier retreat in the western Antarctic Peninsula. Science. 2016;353:283-286.
- 90% of glaciers in the Antarctic Peninsula have retreated since the 1950s. Increasing air temperature was thought to be the main driver of retreat
- Patterns of glacier changes along the west coast show mid-depth ocean temperature is actually the primary control in this region
- Mid-depth ocean warming since the 1990s can explain the acceleration of glacier retreat in the south
Persistent Northward North Atlantic Tropical Cyclone Track Migration Over the Past Five Centuries
Baldini, L.M., Baldini, J.U.L., McElwaine, J., Frappier, A.B., Asmerom, Y., Liu, K.B., Prufer, K., Ridley, H.E., Polyak, V., Kennett, D.J., Macpherson, C.G., Aquino, V.V., Awe, J., and Breitenbach, S.F.M. (2016) Persistent northward North Atlantic tropical cyclone track migration over the past five centuries. Scientific Reports 6: 37522.
- This is the highest resolution, most accurately dated hurricane record ever produced
- The record reveals a northward shift in the dominant Cape Verde tropical cyclone track from the western Caribbean toward the North East US since 1650 CE
- Prior to the Industrial Era, the main TC track shifted together with the Intertropical Convergence Zone
- However, rising anthropogenic greenhouse gases since ~1870 CE are expanding the Hadley Cell (the Bermuda High at the northern limb of the Hadley Cell controls TC track position) is shifting the main TC track toward the North East US despite anthropogenic aerosols causing the ITCZ to shift southward
Pliocene-Pleistocene Evolution of Sea Surface and Intermediate Water Temperatures from the Southwest Pacific
McClymont, E.L., Elmore, A.C., Kender, S., Leng, M.J., Greaves, M. & Elderfield, H. Pliocene-Pleistocene evolution of sea surface and intermediate water temperatures from the southwest Pacific. Paleoceanography. 2016;31:895-913.
- Combination of biomarker (for sea surface temperatures) and foraminifera Mg/Ca (for intermediate water temperatures) analyses
- First reconstruction of Antarctic Intermediate Water temperatures extending beyond the last few glacial-interglacial cycles and into the Pliocene ~3.5 million years ago
- Reconstructed long term trends in temperature reveal shifting positions of subtropical and subantarctic fronts, and likely changes to Southern Ocean sea ice extent
Rapid Thinning of Pine Island Glacier in the Early Holocene
Johnson, J.S., Bentley, M.J., Smith, J.A., Finkel, R.C., Rood, D.H., Gohl, K., Balco, G., Larter, R.D. & Schaefer, J.M. Rapid Thinning of Pine Island Glacier in the Early Holocene. Science. 2014;343:999-1001.
- Reconstruction of past glacier thinning rates at the margins of the Pine Island Glacier
- Age versus elevation of erratic boulders detail thinning history
- Extremely rapid thinning in the early Holocene (>1m/yr) and sustained for long periods
Till: A Glacial Process Sedimentology
Evans D.J.A. (2017) Till: A Glacial Process Sedimentology. Wiley-Blackwell, Chichester.
- Provides the first comprehensive review of the current state of the science on glacial tills
- Refines the interpretations of ancient archives of subglacial processes, specifically those represented by tills and associated deposits, which form the most widespread and accessible record of processes at the ice-bed interface
- Critically reviews the global till literature and experimental and laboratory-based assessments of subglacial processes, as well as the theoretical constructs that have emerged from process sedimentology over the past century
- Develops a more precise, contemporary till nomenclature and new investigatory strategies for understanding a critical aspect of glacial process sedimentology, including:
- an in-depth discussion of subglacial sedimentary processes, with an emphasis on the origins of till matrix and terminal grade and the latest observations on till evolution
- description of contemporary laboratory and modelling experiments on till evolution and techniques for measuring strain signatures in glacial deposits
- development of an updated till nomenclature based on an array of knowledge bases and new strategies for field description and analysis of glacial diamictons