AGW Observer

Observations of anthropogenic global warming

Papers on fossils revealed by melting glaciers

Posted by Ari Jokimäki on September 18, 2009

This is a list of papers on fossils revealed by melting glaciers, and the radiocarbon dating of the fossils. Emphasis is on the samples found in growth position (in situ) and in good condition. That kind of samples suggest that they have been in the ice for the whole period from the time of their burial by ice to the time of the the ice melting and revealing them once again. Such samples also suggest that at the time they were released from ice it was roughly warmer than at any time after their burial in ice. Note that many of the papers presented below are concentrating in revealing historical glacier fluctuations, so they don’t even discuss their findings in the context of the modern climate change (except the few that do discuss it, Thompson et al., 2006, being the prime example). The list is not complete, and will most likely be updated in the future in order to make it more thorough and more representative.

UPDATE (April 18, 2012): Anderson et al. (2008) added. Thanks to Barry for pointing it out (in another paperlist thread).

Latest Pleistocene and Holocene glacier fluctuations in western Canada – Menounos et al. (2009) “We summarize evidence of the latest Pleistocene and Holocene glacier fluctuations in the Canadian Cordillera. Our review focuses primarily on studies completed after 1988, when the first comprehensive review of such evidence was published. … Radiocarbon ages of wood collected from glacier forefields reveal six major periods of glacier advance: 8.59–8.18, 7.36–6.45, 4.40–3.97, 3.54–2.77, 1.71–1.30 ka, and the past millennium.” [Link to PDF]

A millennial perspective on Arctic warming from 14C in quartz and plants emerging from beneath ice caps – Anderson et al. (2008) “Observational records show that the area of ice caps on northern Baffin Island, Arctic Canada has diminished by more than 50% since 1958. Fifty 14C dates on dead vegetation emerging beneath receding ice margins document the persistence of some of these ice caps since at least 350 AD. In situ cosmogenic 14C in rock surfaces, and 14C in plant macrofossils from lake-sediment cores demonstrate that the plateau remained ice-free through the middle Holocene, but has supported ice caps for more than 2000 of the past 2800 years. The rapid disappearance of these ice caps over the past century, despite decreasing summer insolation, further demonstrates the unusual character of 20th Century warmth. Widespread ice-cap expansion ∼1280 AD early in the Little Ice Age, and intensified expansion ∼1450 AD, coincide with peak stratospheric volcanic aerosol loading and reduced solar luminosity, suggesting that these mechanisms may have initiated ice-cap growth, subsequently maintained by strong positive feedbacks.” Anderson, R. K., G. H. Miller, J. P. Briner, N. A. Lifton, and S. B. DeVogel (2008), A millennial perspective on Arctic warming from 14C in quartz and plants emerging from beneath ice caps, Geophys. Res. Lett., 35, L01502, doi:10.1029/2007GL032057. [Full text]

Recent marginal changes of the Mittivakkat Glacier, Southeast Greenland and the discovery of remains of reindeer (Rangifer tarandus), polar bear (Ursus maritimus) and peaty material – Tvis Knudsen et al. (2008) “During field observations in August 2005 antler remains of a reindeer were found at a recently deglaciated site at about 500 m asl., and bones from a polar bear were found at about 300 m asl. along the margin of Mittivakkat Glacier, Southeast Greenland. Radio carbon dating determined the age of the samples to 720 14C years and 350 14C years, respectively. In August 2006 old surface vegetation covering peaty material became exposed due to ice recession close to the site where the antler was found. The radio carbon age of small roots from the material was determined to 1530 14C years, and is in agreement with dating of woody remains of Salix glauca found close by, at the top of a nearby nunatak in 1999. The antler indicates that reindeer lived in the area when the glacier began to advance from a position where it was close to or smaller than today. The vegetation surface and peaty material indicate that the climate was warmer before the onset of the Little Ice Age in Southeast Greenland than today.” [Link to PDF]

Western Canadian glaciers advance in concert with climate change circa 4.2 ka – Menounos et al. (2008) “Disparate climate proxies from the Northern Hemisphere record a climate event at 4.2–3.8 ka. Here we show that glaciers throughout the mountain ranges of western Canada advanced at about this time. This conclusion is based on (1) new and previously reported radiocarbon ages on in situ stumps, logs, branches, and soils exposed by recent retreat in glacier forefields and…” [Link to PDF]

Ice-borne prehistoric finds in the Swiss Alps reflect Holocene glacier fluctuations – Grosjean et al. (2007) “During the hot summer of 2003, reduction of an ice field in the Swiss Alps (Schnidejoch) uncovered spectacular archaeological hunting gear, fur, leather and woollen clothing and tools from four distinct windows of time: Neolithic Age (4900 to 4450 cal. yr BP), early Bronze Age (4100-3650 cal. yr BP), Roman Age (1st-3rd century AD), and Medieval times (8-9th century AD and 14-15th century AD). … The preservation of Neolithic leather indicates permanent ice cover at that site from ca. 4900 cal. yr BP until AD 2003, implying that the ice cover was smaller in 2003 than at any time during the last 5000 years. Current glacier retreat is unprecedented since at least that time. This is highly significant regarding the interpretation of the recent warming and the rapid loss of ice in the Alps.” [Link to PDF]

Pre-`Little Ice Age’ glacier fluctuations in Garibaldi Provincial Park, Coast Mountains, British Columbia, Canada – Koch et al. (2007) “Holocene glacier fluctuations prior to the `Little Ice Age’ in Garibaldi Provincial Park in the British Columbia Coast Mountains were reconstructed from geomorphic mapping and radiocarbon ages on 37 samples of growth-position and detrital wood from glacier forefields. … The first well-documented advance dates to 7700—7300 14C yr BP. Subsequent advances date to 6400—5100, 4300, 4100—2900 and 1600—1100 14C yr BP. … Periods of advance in Garibaldi Park are broadly synchronous with advances elsewhere in the Canadian Cordillera, suggesting a common climatic cause.” [Link to PDF]

Abrupt tropical climate change: Past and present – Thompson et al. (2006) “Finally, rooted, soft-bodied wetland plants, now exposed along the margins as the Quelccaya ice cap (Peru) retreats, have been radiocarbon dated and, when coupled with other widespread proxy evidence, provide strong evidence for an abrupt mid-Holocene climate event that marked the transition from early Holocene (pre-5,000-yr-B.P.) conditions to cooler, late Holocene (post-5,000-yr-B.P.) conditions. … These three lines of evidence argue that the present warming and associated glacier retreat are unprecedented in some areas for at least 5,200 yr.” [Link to PDF]

Multicentury glacier fluctuations in the Swiss Alps during the Holocene – Joerin et al. (2006) “Subfossil remains of wood and peat from six Swiss glaciers found in proglacial fluvial sediments indicate that glaciers were smaller than the 1985 reference level and climatic conditions allowed vegetation growth in now glaciated basins. An extended data set of Swiss glacier recessions consisting of 143 radiocarbon dates is presented to improve the chronology of glacier fluctuations. A comparison with other archives and dated glacier advances suggests 12 major recession periods occurring at 9850- 9600, 9300-8650, 8550-8050, 7700-7550, 7450-6550, 6150-5950, 5700-5500, 5200-4400, 4300-3400, 2800-2700, 2150-1850, 1400-1200 cal. yr BP.” [Link to PDF]

Dendroglaciological Evidence For A Neoglacial Advance Of the Saskatchewan Glacier, Banff National Park, Canadian Rocky Mountains – Wood & Smith (2004) “Seventeen glacially sheared stumps in growth position and abundant detrital wood fragments were exposed by stream avulsion at the terminus of the Saskatchewan Glacier in 1999. The stumps lay buried beneath the glacier and over 5 m of glacial sediment until historical recession and stream incision exposed the 225- to 262-year-old stand of subalpine fir, Englemann spruce and whitebark pine trees. Crossdating and construction of two radiocarbon-controlled floating tree-ring chronologies showed that all the subfossil stumps and boles exposed at this location were killed during a Neoglacial advance of the Saskatchewan Glacier 2,910 ±60 to 2,730 ±60 14C years B.P.” [Link to PDF]

The Alpine “Iceman” and Holocene Climatic Change – Baroni & Orombelli (1996) “The finding of a prehistoric mummified corpse at the upper edge of the accumulation area of an alpine glacier, together with its unique set of artifacts, provided new information on glacier dimensions during the little-known phases of major glacier shrinkage that characterized the warmest parts of the Holocene. The sudden burial of the corpse in a permanent snow cover occurred 5300–5050 cal yr B.P., indicating a significant climatic change that induced glacier expansion at the beginning of Neoglaciation. New geomorphologic data and two AMS14C ages from buried soils suggest that the present glacier size, following over 100 yr of shrinkage, is comparable to that immediately preceding Neoglaciation. Therefore, we can deduce that the current global climatic warming may have interrupted the environmental conditions prevailing in the Alps during Neoglacial time, restoring characteristics similar to those prevailing during theclimatic optimumthat were never achieved during the second half of the Holocene.” [Link to PDF]

Radiocarbon dates from Nordenskjöld Glacier, South Georgia, and their implications for late Holocene glacier chronology – Gordon (1987) “Recent recession of Nordenskjöld Glacier has exposed in situ a bed of peat formerly covered by the glacier. Radiocarbon dates on the peat allow an estimate of the minimum duration of a period of vegetation development and less extensive ice cover than occurs at present between 2230 ± 70 and 3330 ± 120 years BP (equivalent to calendar age ranges of 2122-2334 and 3395-3689 years BP).” [Link to PDF]

Glacier contraction during the middle Holocene in the western Italian Alps: Evidence and implications – Porter & Orombelli (1985) “Radiocarbon dates of peat from the top and base of a bog exposed by recent retreat of Rutor Glacier show that the glacier front terminated upvalley from the bog from 8400 until at least 6000 B.P.”

Entombed Plant Communities Released by a Retreating Glacier at Central Ellesmere Island, Canada – Bergsma et al. (1984) “The release of a dead but well-preserved high arctic plant community, entombed for about 400 radiocarbon years… under glacial ice at Twin Glacier, central Ellesmere Island… is reported. Remarkably intact plants have been emerging from under the ablating front of this polar glacier which has been retreating for several decades at an average rate of 4.1 m yr-1 over the last 22 years. … The excellent preservation of the plants supports the thesis that polar glaciers are frozen to their bases, and hence their movements are by internal deformation rather than by erosive basal sliding.” [Link to PDF]

Preservation of vegetation and patterned ground under a thin ice body in northern Baffin Island, N.W.T. – Falconer (1966), Geographical Bulletin, 8(2): 194-200. Described in Bergsma et al. (1984): “The most relevant work with respect to this report is that of Falconer (1966), who described the release of undisturbed, vegetated patterned ground features by the rapid recesson of a thin body of Tiger Ice Cap in northern Baffin Island. Exposed moss, Polytrichum juniperinum, was radiocarbon-dated at 330 ± 75 years.”

One Response to “Papers on fossils revealed by melting glaciers”

  1. Ari Jokimäki said

    I added Anderson et al. (2008).

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