North American Ice Sheet build-up during the last glacial cycle, 115–21 kyr

Klemån, Johan; Jansson, Krister N.; Angelis, Hernán De; Stroeven, Arjen P.; Hättestrand, Clas; Alm, Göran; Glasser, Neil F.

doi:10.1016/j.quascirev.2010.04.021

Cited by 164 publications

(150 citation statements)

References 60 publications

Supporting

Mentioning

143

Contrasting

Order By: Relevance

“…Despite this, there is currently no detailed glacial geomorphological map recording the spatial distribution of individual subglacial landforms across Newfoundland. This contrasts with the considerable detail of landform mapping and subsequent ice sheet reconstructions carried out for other palaeo-ice sheets, for example, the LIS (Boulton & Clark, 1990;Clark et al, 2000;Kleman et al, 2010).…”

Section: Glacial Landform Mapping In Newfoundlandmentioning

confidence: 86%

“…In addition to providing supporting evidence of former ice flow direction, cross-cutting striae measurements recorded across the island can be integrated as part of an ice sheet reconstruction to aid interpretation of the relative chronologies of former ice flow events (e.g. Jansson et al, 2002;Kleman et al, 2010). Other research approaches have employed Shuttle Radar Topography Mission (SRTM) data to carry out landform mapping in the region.…”

Section: Glacial Landform Mapping In Newfoundlandmentioning

confidence: 99%

“…These latter two, known collectively as the Appalachian Ice Complex, maintained independent ice centres through much of the last glacial cycle (Dyke, 2004;Dyke et al, 2002). The LIS formed the central parts of the North American Ice Sheet Complex and during its maximum extent ( 27 14 C ka BP and 24 14 C ka BP; Dyke et al, 2002) coalesced with the smaller regional ice sheets including the NIS with the convergence zone being along Newfoundland's northern and western margins (Figure 1; Dyke, 2004;Grant, 1989Grant, , 1994Kleman et al, 2010;Stokes, Tarasov, & Dyke, 2012). A southward ice flow from Labrador crossed the Strait of Belle Isle onto northern parts of the Great Northern Peninsula, while further to the south, the LIS advanced as far as the Long Range Mountains before being deflected into the Gulf of St. Lawrence (Brookes, 1982;Catto, 1998;Grant, 1977Grant, , 1989Putt, Bell, Batterson, & Smith, 2010;Shaw et al, 2006;Tucker, 1974).…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

The subglacial imprint of the last Newfoundland Ice Sheet, Canada.

McHenry

Dunlop

2015

Journal of Maps

View full text Add to dashboard Cite

The former Newfoundland Ice Sheet was situated on the fringes of the northeast Atlantic Ocean during the Wisconsinan glaciation ( 80-10 ka BP). Its geographic position indicates that it was likely to have been influenced by a number of external and internal forcing mechanisms including configuration changes in the Laurentide Ice Sheet with which it converged during the last glacial maximum, ice streams, changes in oceanic circulation and fluctuating sea levels. This makes Newfoundland a key location for investigating the dynamic response of ice sheets to these types of internal and external drivers. An established methodology for investigating ice sheet dynamics is to use the landform record to reconstruct the dynamic behaviour and configuration of the ice sheet. This provides a relative chronology of former ice sheet events during glacial cycles. A fundamental requirement of this approach is a detailed glacial geomorphology map that records the spatial distribution of individual subglacial bedforms across the former ice sheet bed. This paper presents a new subglacial bedform map of the Island of Newfoundland. It was produced as part of a mapping programme which used 10 m resolution Satellite Pour l'Observation de la Terre satellite imagery, Shuttle Radar Topography Mission and Canadian Digital Elevation Data. The map records the spatial distribution of 126,000 individually mapped glacial lineations and ribbed moraines and extends the number and spatial extent of each landform across the island. It is a new data set which has the potential to provide important insights into former ice sheet behaviour in this region.

show abstract

Section: Glacial Landform Mapping In Newfoundlandmentioning

confidence: 86%

Section: Glacial Landform Mapping In Newfoundlandmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

The subglacial imprint of the last Newfoundland Ice Sheet, Canada.

McHenry

Dunlop

2015

Journal of Maps

View full text Add to dashboard Cite

show abstract

“…3 B and E MIS 4 was a time of high global ice volume (38), but the North American ice sheet was limited to the northeastern quadrant of the continent (Fig. 1B) (39). Atmospheric circulation simulations indicate that a persistent anticyclone developed above the MIS 4 ice sheet, which combined with the eastern location of the ice sheet, created a corridor of northwestward-moving summer winds through central North America, perhaps as far north as Alaska, whereas winters continued to be dominated by largely unchanged westerly winds (32).…”

Section: North American Paleoclimate Revealed By Pedothem Datamentioning

confidence: 99%

Pedothem carbonates reveal anomalous North American atmospheric circulation 70,000–55,000 years ago

Oerter

Sharp

Oster

et al. 2016

Proc. Natl. Acad. Sci. U.S.A.

View full text Add to dashboard Cite

Our understanding of climatic conditions, and therefore forcing factors, in North America during the past two glacial cycles is limited in part by the scarcity of long, well-dated, continuous paleoclimate records. Here, we present the first, to our knowledge, continuous, millennial-resolution paleoclimate proxy record derived from millimeter-thick pedogenic carbonate clast coatings (pedothems), which are widely distributed in semiarid to arid regions worldwide. Our new multiisotope pedothem record from the Wind River Basin in Wyoming confirms a previously hypothesized period of increased transport of Gulf of Mexico moisture northward into the continental interior from 70,000 to 55,000 years ago based on oxygen and carbon isotopes determined by ion microprobe and uranium isotopes and U-Th dating by laser ablation inductively coupled plasma mass spectrometry. This pronounced meridional moisture transport, which contrasts with the dominant zonal transport of Pacific moisture into the North American interior by westerly winds before and after 70,000–55,000 years ago, may have resulted from a persistent anticyclone developed above the North American ice sheet during Marine Isotope Stage 4. We conclude that pedothems, when analyzed using microanalytical techniques, can provide high-resolution paleoclimate records that may open new avenues into understanding past terrestrial climates in regions where paleoclimate records are not otherwise available. When pedothem paleoclimate records are combined with existing records they will add complimentary soil-based perspectives on paleoclimate conditions.

show abstract

“…It is now generally accepted that the inception required orbital and GHG forcings acting together along with various feedback processes. Sea ice, snow albedo, sea surface temperature and vegetation changes all play important roles (Khodri et al 2001;Meisner and Gerdes 2002;Meisner et al 2003;Kageyama et al 2004;Desprat et al 2005;Roe 2006;Crucifix et al 2006;Kubatzki et al 2006;Krinner et al 2006;Schurgers et al 2007;Calov et al 2009, Gorbarenko et al 2010, Kleman et al 2011. Only a few of these studies attempted to find links between glacial inception and changes in global atmospheric circulation, particularly over the Pacific Ocean.…”

Section: Introductionmentioning

confidence: 99%

Atmospheric circulation anomalies due to 115 kyr BP climate forcing dominated by changes in the North Pacific Ocean

2011

View full text Add to dashboard Cite

Climate at the time of inception of the Laurentide Ice Sheet (LIS) at ~115 kyr BP is simulated with the fully coupled NCAR Community Climate System Model (CCSM3) and compared to a simulated preindustrial climate (circa 1870) in order to better understand land surface and atmospheric responses to orbital and greenhouse cooling at inception. The interaction between obliquity and eccentricity produces maximum decrease in TOA insolation in JJA over the Arctic but increases occur over the tropics in DJF. The land surface response is dominated by widespread summer cooling in the Northern Hemisphere (NH), increases in snowfall, and decreases in melt rates and total precipitation. CCSM3 responds to the climate forcing at 115 kyr BP by producing incipient glaciation in the areas of LIS nucleation.We find that the inception of the LIS could have occurred with atmospheric IntroductionThe inception of the Laurentide Ice Sheet (LIS) over the Canadian Arctic has been the subject of many previous studies. It is now generally accepted that the inception required orbital and GHG forcings acting together along with various feedback processes. Sea ice, snow albedo, sea surface temperature and vegetation changes all play important roles (Khodri et al. 2001;Meisner and Gerdes 2002;Meisner et al. 2003;Kageyama et al. 2004;Desprat et al. 2005;Roe 2006;Crucifix et al. 2006;Kubatzki et al. 2006;Krinner et al. 2006;Schurgers et al. 2007;Calov et al. 2009, Gorbarenko et al. 2010, Kleman et al. 2011. Only a few of these studies attempted to find links between glacial inception and changes in global atmospheric circulation, particularly over the Pacific Ocean. Also most of the studies used simplified models to examine the impacts of orbital, greenhouse gas (GHG) and surface forcings. The earlier results suggested that neither orbital nor GHG forcings alone were sufficient for inception. However, more recent studies that include detailed physics and account for model bias, in for example sea surface temperatures was simulated using a land surface model with idealized atmospheric forcing. In the study, the atmospheric forcing (wind speeds, temperature, precipitation and specific humidity) was held constant while the insolation and CO 2 concentrations were modified to conform to the end of the Eemian ~116 kyr before present (116 kyr BP).The study found that even if an atmospheric circulation pattern similar to the one that produced the coldest summer in the last 50 years was maintained perpetually in a simulation, the local reduction in insolation and CO 2 was insufficient for LIS inception. Even in this highly idealized environment, additional cooling of 4 o C was still needed for inception. Conversely, no inception occurred when the summer air temperature was specified using representative present-day values even under the perpetual extreme winter snowfall, decreased insolation and lower GHG concentrations. How the widespread cooling could have occurred in reality was not addressed. In this study we expand on the earlier work by exa...

show abstract

North American Ice Sheet build-up during the last glacial cycle, 115–21 kyr

Cited by 164 publications

References 60 publications

The subglacial imprint of the last Newfoundland Ice Sheet, Canada.

The subglacial imprint of the last Newfoundland Ice Sheet, Canada.

Pedothem carbonates reveal anomalous North American atmospheric circulation 70,000–55,000 years ago

Atmospheric circulation anomalies due to 115 kyr BP climate forcing dominated by changes in the North Pacific Ocean

Contact Info

Product

Resources

About