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Overview and Significance of a 250 Ka Paleoclimate Record from El J Paleolimnol (2007) 37:1–16 DOI 10.1007/s10933-006-9017-6 ORIGINAL PAPER Overview and significance of a 250 ka paleoclimate record from El’gygytgyn Crater Lake, NE Russia Julie Brigham-Grette Æ Martin Melles Æ Pavel Minyuk Æ Scientific Party Received: 3 April 2006 / Accepted: 1 May 2006 / Published online: 9 December 2006 Ó Springer Science+Business Media B.V. 2006 Abstract Sediment piston cores from Lake to changes in the limnogeology and the biogeo- El’gygytgyn (67°N, 172°E), a 3.6 million year old chemistry that reflect robust changes in the meteorite impact crater in northeastern Siberia, regional climate and paleoecology over a large have been analyzed to extract a multi-proxy mil- part of the western Arctic. Third, the magnetic lennial-scale climate record extending to nearly susceptibility and other proxies record numerous 250 ka, with distinct fluctuations in sedimento- rapid change events. The recovered lake sediment logical, physical, biochemical, and paleoecologi- contains both the best-resolved record of the last cal parameters. Five major themes emerge from interglacial and the longest terrestrial record of this research. First the pilot cores and seismic data millennial scale climate change in the Arctic, show that El’gygytygn Crater Lake contains what yielding a high fidelity multi-proxy record is expected to be the longest, most continuous extending nearly 150,000 years beyond what has terrestrial record of past climate change in the been obtained from the Greenland Ice Sheet. entire Arctic back to the time of impact. Second, Fourth, the potential for evaluating teleconnec- processes operating in the El’gygytygn basin lead tions under different mean climate states is high. Despite the heterogeneous nature of recent Arc- tic climate change, millennial scale climate events This is the first in a series of eleven papers published in this special issue dedicated to initial studies of El’gygytgyn in the North Atlantic/Greenland region are re- Crater Lake and its catchment in NE Russia. Julie Brig- corded in the most distal regions of the Arctic ham-Grette, Martin Melles, Pavel Minyuk were guest under variable boundary conditions. Finally, deep editors of this special issue. drilling of the complete depositional record in Lake El’gygytgyn will offer new insights and, J. Brigham-Grette (&) Department of Geosciences, University of perhaps, surprises into the late Cenozoic evolu- Massachusetts, Amherst, MA 01003, USA tion of Arctic climate. e-mail: [email protected] Keywords Paleoclimate Æ Paleolimnology Æ M. Melles Institute for Geology and Geophysics, University of Arctic Æ Beringia Æ Chukotka Æ El’gygytgyn Leipzig, Leipzig, Germany Introduction P. Minyuk North-East Interdisciplinary Science Research Institute FEB RAS, 685000 Magadan16 Portovaya St., The Arctic is currently experiencing environmen- Russia tal warming and change at rates unprecedented in 123 2 J Paleolimnol (2007) 37:1–16 historical times causing wholesale ecosystem Core Project members 2004) provide compelling migrations (Bradley et al. 2003; Grebmeier et al. justification for study of lengthy continuous 2006; Overpeck et al. 2005). Large international lacustrine records in the Arctic. programs (e.g., ACIA 2005; SEARCH 2005) have Long high-resolution multiproxy lake records been launched to monitor this change and develop that evaluate the terrestrial response to regional models for predicting the magnitude and regional global change are rapidly emerging from both the repercussions of future environmental change. northern and southern hemisphere (e.g., Colman Without question, the polar regions play a major et al. 1995; Cohen et al. 2000; Baker et al. 2001a, role in the global climate system, balancing the b; Wang et al. 1991; Seltzer et al. 2002; Ansel- input of solar energy to the tropics thereby influ- metti et al., in press). Millennial scale records are encing both oceanic and atmospheric circulation also rapidly emerging from areas of the tropics through strong feedback interactions involving and subtropics for comparison (e.g., Behl and ocean, atmosphere, cryosphere, and terrestrial Kennett 1996; Schulz et al. 1998; Hughen et al. processes (Otto-Bliesner et al. 2006; Overpeck 2000; Peterson et al. 2000; Wang et al. 2001; Stott et al. 2006). In fact, much Arctic research today is et al. 2002; Koutavas et al. 2002; Lea et al. 2000, anchored in the premise that accurate predictions 2003; Burns et al. 2003) causing scientists to re- about future climate evolution and related envi- think the role of the tropics vs. the high latitudes ronmental change depends on our capacity to in climate change on millennial and finer time document and recognize the function of the Arctic scales. region in modulating past change under different Across the Arctic borderlands, El’gygytgyn climate-forcing conditions, including those possi- Lake uniquely contains a sediment record com- bly forced on the Arctic from the tropics (Clement parable to these other archives. After all, El’gy- and Cane 1999; Cane and Clement 1999). Robust gytgyn Crater (67.5°N and 172°E; Fig. 1) was predictions of a warmer future (IPCC 2001; Over- formed by a meteorite impact 3.6 million years peck et al. 2006) require a geologic perspective on ago (Layer 2000). At that time, most of the Arctic the dynamic range of environmental change in the was forested at least periodically all the way to high latitudes, especially given polar amplification northern Ellesmere Island, the Arctic Ocean during previous interglacial periods and past lacked sea ice, and the Greenland Ice Sheet did intervals of rapid change (CAPE 2006). not exist in its present form (Brigham-Grette and Teleconnections and the propagation of Carter 1992 and references therein). In fact after change between the Arctic and the global climate the meteorite hit, nearly a million years passed system can only be assessed by comparing well- before the first glaciation of the Northern Hemi- dated Arctic terrestrial, marine, and ice-core cli- sphere began (cf. Haug et al. 2005). Perhaps what mate archives, especially over several glacial/ makes it unique is that this meteorite landed interglacial cycles when Milancovitch and mil- nearly in the center of what was to become lennial scale forcings of Northern Hemisphere Beringia—the largest contiguous landscape in the boundary conditions were altered (cf., Stott et al. Arctic to have escaped Northern Hemisphere 2002). Long marine records are relatively com- glaciation (Fig. 2), consequently creating a lake mon, yet few long terrestrial records exist in the basin that would continuously chronicle the lon- Arctic with a temporal resolution at least as good gest terrestrial record of paleoclimate in the cir- as the deep marine record. Emphasis on the cumarctic. higher resolution millennial-scale paleoclimatic The purpose of this special issue is to summa- marine records of the Arctic gateway regions rize what is known of the modern Lake El’gy- (e.g., Wolf and Thiede 1991; Keigwin et al. 1994; gytgyn basin and to synthesize studies of a pilot Rea et al. 1995; Spielhagen et al. 1997, 2004; core first taken to determine the scientific prom- Keigwin 1998; Helmke et al. 2002; Backman et al. ise of this exceptional lake system for deep dril- 2004), and the arguably shorter records available ling as a key northern hemisphere archive of past from the Greenland Ice Sheet (e.g., Grootes et al. environmental change. The papers are based on 1993; Johnsen et al. 2001; North Greenland Ice results from the first 2 of 3 American–German– 123 J Paleolimnol (2007) 37:1–16 3 Fig. 2 Arctic geography showing the extent of large ice sheets during the Last Glacial Maximum, 20 ka BP, and the position of Lake El’gygytgyn (solid star) within the largest contiguous terrestrial area to have escaped North- ern Hemisphere glaciation. Small valley glacier complexes in mountainous regions are not shown. Open stars in the Sea of Okhotsk (Nu¨ rnberg and Tiedemann 2004), deep Fig. 1 Location of Lake El’gygytgyn, 100 km north of the Bering Sea (Beth Caissie unpublished), Arctic Ocean– Arctic Circle in northeastern Russia. (a) Location of Lake Lomonosov Ridge (Backman et al. 2004), Greenland El’gygytgyn relative to other key lacustrine basins in (Johnsen et al. 2001) and off the coast of Portugal Beringia with long sediment records including Elikchan (Chappell and Shackleton 1999) highlight key marine Lake (65 kyrs, Lozhkin and Anderson 1996); Imuruk Lake and ice core records to be used for evaluating teleconnec- (130 kyrs, Colinvaux 1964); Squirrel Lake (180 kyrs, tions and the regional vs. global aspects of the paleocli- Berger and Anderson 2000); Ahaliorak Lake (130 kyrs, mate record from Lake El’gygytgyn Eisner and Colinvaux 1990, Anderson and Brubaker unpublished). (b) Topography of El’gygytgyn crater and bathymetry of the modern lake system showing the location of core PG1351 began studies of the modern lake system and its catchment. The primary goal of this program was to Russian expeditions to the lake. Sediment cores conduct the first seismic reflection surveys of the were initially taken from the center of the lake in bedrock and sediment stratigraphy but also to May, 1998, using gravity and percussion piston learn about the modern limnology, geomorphol- corers and the 2 m thick lake ice as a coring ogy, surficial stratigraphy, Holocene sedimentol- platform (Fig. 1). Core PG1351 from a water ogy, lake hydrology and meteorology in addition to depth of 170 m penetrates about 13 m of the lake ground-truth remote sensing efforts and DEM sediment record. development (Nolan et al. 2002). First results of a Preliminary results from this core were first re- major spring and summer-long field campaign to ported at the Fall AGU in 1999 and 2000. Nowa- the lake in 2003 to improve the resolution of the czyk et al. (2002) published the first core seismic data, collect new piston cores, and continue chronology based upon magnetic susceptibility process studies are reported in other publications measurements, optical luminescence ages, and (Melles et al.
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