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Multivariate Statistic and Time Series Analyses of Grain-Size Data in Quaternary Sediments of Lake El’Gygytgyn, NE Russia

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Multivariate Statistic and Time Series Analyses of Grain-Size Data in Quaternary Sediments of Lake El’Gygytgyn, NE Russia Clim. Past, 9, 2459–2470, 2013 Open Access www.clim-past.net/9/2459/2013/ Climate doi:10.5194/cp-9-2459-2013 © Author(s) 2013. CC Attribution 3.0 License. of the Past Multivariate statistic and time series analyses of grain-size data in quaternary sediments of Lake El’gygytgyn, NE Russia A. Francke1, V. Wennrich1, M. Sauerbrey1, O. Juschus2, M. Melles1, and J. Brigham-Grette3 1University of Cologne, Institute for Geology and Mineralogy, Cologne, Germany 2Eberswalde University for Sustainable Development, Eberswalde, Germany 3University of Massachusetts, Department of Geosciences, Amherst, USA Correspondence to: A. Francke ([email protected]) Received: 14 December 2012 – Published in Clim. Past Discuss.: 14 January 2013 Revised: 20 September 2013 – Accepted: 3 October 2013 – Published: 5 November 2013 Abstract. Lake El’gygytgyn, located in the Far East Rus- glacial–interglacial variations (eccentricity, obliquity), and sian Arctic, was formed by a meteorite impact about 3.58 Ma local insolation forcing and/or latitudinal teleconnections ago. In 2009, the International Continental Scientific Drilling (precession), respectively. Program (ICDP) at Lake El’gygytgyn obtained a continu- ous sediment sequence of the lacustrine deposits and the up- per part of the impact breccia. Here, we present grain-size data of the past 2.6 Ma. General downcore grain-size varia- 1 Introduction tions yield coarser sediments during warm periods and finer The polar regions are known to play a crucial but not ones during cold periods. According to principal component yet well understood role within the global climate system analysis (PCA), the climate-dependent variations in grain- (Washington and Meehl, 1996; Johannessen et al., 2004), in- size distributions mainly occur in the coarse silt and very fluencing both the oceanic and the atmospheric circulation. fine silt fraction. During interglacial periods, accumulation The recent global warming trend has been, and is predicted to of coarser material in the lake center is caused by redistri- be, most pronounced in the Arctic (ACIA, 2004; Serreze and bution of clastic material by a wind-induced current pattern Francis, 2006). However, rather little is known about the nat- during the ice-free period. Sediment supply to the lake is ural and environmental variability on geological timescales. triggered by the thickness of the active layer in the catch- Our current knowledge on the Cenozoic climate evolution of ment and the availability of water as a transport medium. the Arctic has long been based on sparse, often discontinuous During glacial periods, sedimentation at Lake El’gygytgyn marine and terrestrial paleorecords of the Arctic Ocean and is hampered by the occurrence of a perennial ice cover, adjacent landmasses (Thiede et al., 1998; Moran et al., 2006; with sedimentation being restricted to seasonal moats and Axford et al., 2009; Pienitz et al., 2009; Zech et al., 2011). vertical conduits through the ice. Thus, the summer tem- The first continuous Pliocene–Pleistocene sediment record perature predominantly triggers transport of coarse material in the terrestrial Arctic was recovered in 2009 during a deep into the lake center. Time series analysis that was carried drilling campaign of the International Continental Scien- out to gain insight into the frequency of the grain-size data tific Drilling Program (ICDP) at Lake El’gygytgyn in the showed variations predominately on 98.5, 40.6, and 22.9 kyr Far East Russian Artic (Fig. 1; Melles et al., 2011). Pi- oscillations, which correspond to Milankovitch’s eccentric- lot studies on Lake El’gygytgyn sediments covering the ity, obliquity and precession bands. Variations in the relative last 2–3 glacial–interglacial cycles had already demonstrated power of these three oscillation bands during the Quaternary the usability of this archive for paleoclimate reconstruc- suggest that sedimentation processes at Lake El’gygytgyn tions (e.g. Brigham-Grette et al., 2007; Melles et al., 2007; are dominated by environmental variations caused by global Niessen et al., 2007). Initial results from the upper part Published by Copernicus Publications on behalf of the European Geosciences Union. 2460 A. Francke et al.: Multivariate statistic and time series analyses of grain-size data of the 318 m-long sediment record in central parts of the lake (ICDP site 5011-1) provided first details of Quaternary A 140°E 160° 180° 220° 240° 65° history, focusing on interglacial variability during the past N Artic Ocean 2.8 Myr (Melles et al., 2012). Russia Alaska Here, we present new results of granulometric analyses on 60° Magadan ICDP core 5011-1 throughout the past 2.6 Myr. Grain-size Fairbanks data have extensively been used before as a paleoenviron- 55° mental and -climatological proxy on long terrestrial and la- custrine sedimentary records, including those from the Chi- Bering 50° Sea nese Loess Plateau (e.g. An et al., 1991; Sun and Huang, 2006; Sun et al., 2006) and from lakes Baikal (Kashiwaya et al., 1998, 2001) and Biwa (Kashiwaya et al., 1987). At Lake El´gygytgyn Lake El’gygytgyn, previous studies of grain-size variations are widely restricted to the sediments formed during the past B 65 ka (Asikainen et al., 2007). During this period, particle- 67°35’ size variations were predominantly controlled by the regional climatic settings and their impacts on the physical properties in the lake and its catchment. Our grain-size investigations on A ICDP core 5011-1 extend the results from this early research 21 67°30’ 16 1 7 to the entire Quaternary. Furthermore, we incorporated more 0 14 m 1 6 B recent findings on the modern climatological, hydrological, 0 1 m 12 5 49 0 and sedimentological settings (Fedorov et al., 2013; Nolan et m al., 2013; Wennrich et al., 2013a). To better understand the Camp sedimentological processes operating in Lake El’gygytgyn, 67°25’ Enmyvaam we used principal component analysis (PCA) to detect dom- 320 500 700 inating variations in the grain-size distributions, and we em- 900 5 km meter 171°40’ a.s.l. 171°40’ 172°00’ 172°10’ ployed time series analysis to reveal oscillations in the gran- 172°20’ ulometric data and their relative dominance over time. C NW SE 2 Site information A B Lake El'gygytgyn 5011-1 Lake El’gygytgyn is located in the Far East Russian Arc- water column ◦ 0 (170 m at 5011-1) tic, in the central part of the Chukchi Peninsula (67 30 N, Lz1024 A B C 0 m sediments 172◦050 E, 492 m a.s.l.; Fig. 1). It is formed within a mete- Unit 1 (Quaternary) Lacustrine supposed 123 m talik/permafrost orite impact crater (e.g. Dietz and McHone, 1977; Gurov et border Unit 2 (Pliocene) 318 m al., 1979) dated to about 3.58 Ma (Layer, 2000). The lake has Impact polymictic and rocks suevitic breccia a nearly circular shape with a diameter of about 12 km and central 420 m monomictic breccia uplift 517 m and fractured bedrock 0 1 2km a depth of about 175 m (Nolan and Brigham-Grette, 2007), Faults associated with central ring whereas the catchment confined by the crater rim measures Lacustrine sediments Permafrost sediments Impact rock Core loss/gap about 18 km in diameter (corresponding to 293 km2). Today, Fig. 1. (A) Location of Lake El’gygytgyn in the Far East Russian the lake is not located in the center of the crater but slightly Artic; (B) bathymetric map of the lake and topographic map of the displaced to the southeast, resulting in an asymmetric catch- catchment area, including the approximately 50 inlet streams and the Enmyvaam River outlet (Fedorov and Kupolov, 2005); red line: ment area (Fig. 1). profile A to B. (C) Schematic profile A to B with the locations of The El’gygytgyn crater region is part of the central the pilot core Lz 1024 and the three holes (A, B and C) at ICDP site Chukchi sector of the Okhotsk–Chukchi volcanic belt (Gurov 5011-1 with the Pliocene–Pleistocene boundary penetrated at ap- and Gurova, 1979; Gurov et al., 2007). It is dominated proximately 123 m, and the transition to the impact breccia at 318 m by acid volcanic rocks, ignimbrites and tuffaceous clastic below lake floor (modified after Melles et al., 2011). rocks of the late Cretaceous (e.g. Gurov et al., 2007; Stone et al., 2009). The lake is surrounded by continuous per- mafrost, whose onset can presumably be traced back to the catchment is predominantly affected by permafrost processes late Pliocene (Glushkova and Smirnov, 2007), and which such as solifluction and cryogenic weathering (Glushkova is assumed to have a thickness of about 330–360 m with and Smirnov, 2007). In addition, distinct lake-level varia- an unfrozen talik underneath the lake today (Mottaghy et tions during the Middle Pleistocene to Holocene modified al., 2013). The recent geomorphologic shape of the lake the geomorphic shape of the area and resulted in various Clim. Past, 9, 2459–2470, 2013 www.clim-past.net/9/2459/2013/ A. Francke et al.: Multivariate statistic and time series analyses of grain-size data 2461 accumulative and erosional terraces at 35–40, 9–11 and 2.5– 3 Material and methods 3.0 m above as well as 10 m below the modern lake level (Glushkova and Smirnov, 2007; Juschus et al., 2011). The catchment of Lake El’gygytgyn is dissected by ap- Within the scope of this study, 1019 samples of Lake proximately 50 ephemeral inlet streams (see Fig. 1; Nolan El’gygytgyn sediments originating from pelagic sediments and Brigham-Grette, 2007), which deliver sediment in the in core composite of ICDP site 5011-1 (862 samples) and order of ca. 350 t yr−1 into the lake (Fedorov et al., 2013).
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