TY  - GEN
A1  - Kienel, Ulrike
A1  - Wulf Bowen, Sabine
A1  - Byrne, Roger
A1  - Park, Jungjae
A1  - Böhnel, Harald
A1  - Dulski, Peter
A1  - Luhr, James F.
A1  - Siebert, Lee
A1  - Haug, Gerald H.
A1  - Negendank, Jörg F. W.
T1  - First lacustrine varve chronologies from Mexico
BT  - impact of droughts, ENSO and human activity since AD 1840 as recorded in maar sediments from Valle de Santiago
T2  - Postprints der Universität Potsdam : Mathematisch Naturwissenschaftliche Reihe
N2  - We present varve chronologies for sediments from two maar lakes in the Valle de Santiago region (Central Mexico): Hoya La Alberca (AD 1852-1973) and Hoya Rincn de Parangueo (AD 1839-1943). These are the first varve chronologies for Mexican lakes. The varved sections were anchored with tephras from Colima (1913) and Paricutin (1943/1944) and (210)Pb ages. We compare the sequences using the thickness of seasonal laminae and element counts (Al, Si, S, Cl, K, Ti, Mn, Fe, and Sr) determined by micro X-ray fluorescence spectrometry. The formation of the varve sublaminae is attributed to the strongly seasonal climate regime. Limited rainfall and high evaporation rates in winter and spring induce precipitation of carbonates (high Ca, Sr) enriched in (13)C and (18)O, whereas rainfall in summer increases organic and clastic input (plagioclase, quartz) with high counts of lithogenic elements (K, Al, Ti, and Si). Eolian input of Ti occurs also in the dry season. Moving correlations (5-yr windows) of the Ca and Ti counts show similar development in both sequences until the 1930s. Positive correlations indicate mixing of allochthonous Ti and autochthonous Ca, while negative correlations indicate their separation in sublaminae. Negative excursions in the correlations correspond with historic and reconstructed droughts, El Nio events, and positive SST anomalies. Based on our data, droughts (3-7 year duration) were severe and centred around the following years: the early 1850s, 1865, 1880, 1895, 1905, 1915 and the late 1920s with continuation into the 1930s. The latter dry period brought both lake systems into a critical state making them susceptible to further drying. Groundwater overexploitation due to the expansion of irrigation agriculture in the region after 1940 induced the transition from calcite to aragonite precipitation in Alberca and halite infiltration in Rincn. The proxy data indicate a faster response to increased evaporation for Rincn, the lake with the larger maar dimensions, solar radiation receipt and higher conductivity, whereas the smaller, steeper Alberca maar responded rapidly to increased precipitation.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 860 
KW  - varve chronology
KW  - tephra
KW  - element chemistry
KW  - drought
KW  - human impact
KW  - El Nino
KW  - Mexico
Y1  - 2020
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-432794
SN  - 1866-8372
IS  - 860
SP  - 587
EP  - 609
ER  - 
TY  - JOUR
A1  - Bakke, Jostein
A1  - Lie, Øyvind
A1  - Heegaard, Einar
A1  - Dokken, Trond
A1  - Haug, Gerald H.
A1  - Birks, Hilary H.
A1  - Dulski, Peter
A1  - Nilsen, Trygve
T1  - Rapid oceanic and atmospheric changes during the Younger Dryas cold period
N2  - The Younger Dryas event, which began approximately 12,900 years ago, was a period of rapid cooling in the Northern Hemisphere, driven by large-scale reorganizations of patterns of atmospheric and oceanic circulation(1-3). Environmental changes during this period have been documented by both proxy-based reconstructions(3) and model simulations(4), but there is currently no consensus on the exact mechanisms of onset, stabilization or termination of the Younger Dryas(5-8). Here we present high-resolution records from two sediment cores obtained from Lake Krakenes in western Norway and the Nordic seas. Multiple proxies from Lake Krakenes are indicative of rapid alternations between glacial growth and melting during the later Younger Dryas. Meanwhile, reconstructed sea surface temperature and salinity from the Nordic seas show an alternation between sea-ice cover and the influx of warm, salty North Atlantic waters. We suggest that the influx of warm water enabled the westerly wind systems to drift northward, closer to their present-day positions. The winds thus brought relatively warm maritime air to Northern Europe, resulting in rising temperatures and the melting of glaciers. Subsequent input of this fresh meltwater into the ocean spurred the formation of sea ice, which forced the westerly winds back to the south, cooling Northern Europe. We conclude that rapid alternations between these two states immediately preceded the termination of the Younger Dryas and the permanent transition to an interglacial state.
Y1  - 2009
UR  - http://www.nature.com/ngeo/index.html
U6  - https://doi.org/10.1038/ngeo439
SN  - 1752-0894
ER  - 
TY  - JOUR
A1  - Jaccard, Samuel Laurent
A1  - Galbraith, Eric D.
A1  - Sigman, Daniel M.
A1  - Haug, Gerald H.
A1  - Francois, Roger
A1  - Pedersen, Thomas F.
A1  - Dulski, Peter
A1  - Thierstein, Hans R.
T1  - Subarctic Pacific evidence for a glacial deepening of the oceanic respired carbon pool
N2  - Measurements of benthic foraminiferal cadmium:calcium (Cd/Ca) have indicated that the glacial-interglacial change in deep North Pacific phosphate (PO4) concentration was minimal which has been taken by some, workers as a sign that the biological pump did not store more carbon in the deep glacial ocean. Here we present sedimentary redox- sensitive trace metal records from Ocean Drilling Program (ODP) Site 882 (NW subarctic Pacific, water depth 3244 m) to make inferences about changes in deep North Pacific oxygenation and thus respired carbon storage - over the past 150,000 yr. These observations are complemented with biogenic barium and opal measurements as indicators for past organic carbon export to separate the influences of deep-water oxygen concentration and sedimentary organic carbon respiration on the redox state of the sediment. Our results suggest that the deep subarctic Pacific water mass was deleted in ox en during glacial maxima, though it was not anoxic. We reconcile our results with the existing benthic foraminiferal Cd/Ca by invoking a decrease in the fraction of the deep ocean nutrient inventory that was preformed, rather than remineralized. This change would have corresponded to an increase in the deep Pacific storage of respired carbon, which Would have lowered atmospheric carbon dioxide (CO2) by sequestering CO2 away from the atmosphere and by increasing ocean alkalinity through a transient dissolution event in the deep sea. The magnitude of change in preformed nutrients suggested by the North Pacific data Would have accounted for a majority of the observed decrease in glacial atmospheric PCO2.
Y1  - 2009
UR  - http://www.sciencedirect.com/science/journal/0012821X
U6  - https://doi.org/10.1016/j.epsl.2008.10.017
SN  - 0012-821X
ER  - 
TY  - JOUR
A1  - Kienel, Ulrike
A1  - Bowen, Sabine Wulf
A1  - Byrne, Roger
A1  - Park, Jungjae
A1  - Boehnel, Harald
A1  - Dulski, Peter
A1  - Luhr, James F.
A1  - Siebert, Lee
A1  - Haug, Gerald H.
A1  - Negendank, Joerg F. W.
T1  - First lacustrine varve chronologies from Mexico : impact of droughts, ENSO and human activity since AD 1840 as recorded in maar sediments from Valle de Santiago
N2  - We present varve chronologies for sediments from two maar lakes in the Valle de Santiago region (Central Mexico): Hoya La Alberca (AD 1852-1973) and Hoya Rincn de Parangueo (AD 1839-1943). These are the first varve chronologies for Mexican lakes. The varved sections were anchored with tephras from Colima (1913) and Paricutin (1943/ 1944) and Pb-210 ages. We compare the sequences using the thickness of seasonal laminae and element counts (Al, Si, S, Cl, K, Ti, Mn, Fe, and Sr) determined by micro X-ray fluorescence spectrometry. The formation of the varve sublaminae is attributed to the strongly seasonal climate regime. Limited rainfall and high evaporation rates in winter and spring induce precipitation of carbonates (high Ca, Sr) enriched in C-13 and O-18, whereas rainfall in summer increases organic and clastic input (plagioclase, quartz) with high counts of lithogenic elements (K, Al, Ti, and Si). Eolian input of Ti occurs also in the dry season. Moving correlations (5-yr windows) of the Ca and Ti counts show similar development in both sequences until the 1930s. Positive correlations indicate mixing of allochthonous Ti and autochthonous Ca, while negative correlations indicate their separation in sublaminae. Negative excursions in the correlations correspond with historic and reconstructed droughts, El Nio events, and positive SST anomalies. Based on our data, droughts (3-7 year duration) were severe and centred around the following years: the early 1850s, 1865, 1880, 1895, 1905, 1915 and the late 1920s with continuation into the 1930s. The latter dry period brought both lake systems into a critical state making them susceptible to further drying. Groundwater overexploitation due to the expansion of irrigation agriculture in the region after 1940 induced the transition from calcite to aragonite precipitation in Alberca and halite infiltration in Rincn. The proxy data indicate a faster response to increased evaporation for Rincn, the lake with the larger maar dimensions, solar radiation receipt and higher conductivity, whereas the smaller, steeper Alberca maar responded rapidly to increased precipitation.
Y1  - 2009
UR  - http://www.springerlink.com/content/100294
U6  - https://doi.org/10.1007/s10933-009-9307-x
SN  - 0921-2728
ER  - 
TY  - JOUR
A1  - Prasad, Sushama
A1  - Witt, Annette
A1  - Kienel, Ulrike
A1  - Dulski, Peter
A1  - Bauer, Eva
A1  - Yancheva, Gergana
T1  - The 8.2 ka event : evidence for seasonal differences and the rate of climate change in western Europe
N2  - Recent studies have drawn attention to differences in the seasonal impact of the 8.2 ka event, with longer cooler summers and shorter cooler/drier winters. However, there are no data available on the simultaneity or the rate of onset of the seasonal changes in Europe. Based on the microfacies and geochemical analyses of seasonally laminated varved sediments from Holzmaar, we present evidence of differences in duration and onset time of changes in summer temperature and winter rainfall during the 8.2 ka event. Since both summer and winter climate signals are co-registered within a single varve, there can be no ambiguity about the phasing and duration of the signals. Our data show that the onset and withdrawal of the 8.2 ka summer cooling occurred within a year, and that summer rains were reduced or absent during the investigated period. The onset of cooler summers preceded the onset of winter dryness by ca. 28 years. In view of the differences in nature and duration of the impact of the 8.2 ka event we suggest that a clearer definition of the 8.2 ka event (summer cooling or winter cooling/dryness) needs to be developed. Based on regional comparison and available modelling studies we also discuss the roles of solar variability, changes in North Atlantic Thermohaline circulation, and North Atlantic Circulation (NAO) during the period under consideration. Wavelet analyses of seasonal laminae indicates that the longer NAO cycles, linked to changes in the N. Atlantic temperatures, were more frequent during the drier periods.
Y1  - 2009
UR  - http://www.sciencedirect.com/science/journal/09218181
U6  - https://doi.org/10.1016/j.gloplacha.2009.03.011
SN  - 0921-8181
ER  - 
TY  - JOUR
A1  - Anoop, Ambili
A1  - Prasad, Sushma
A1  - Krishnan, R.
A1  - Naumann, Rudolf
A1  - Dulski, Peter
T1  - Intensified monsoon and spatiotemporal changes in precipitation patterns in the NW Himalaya during the early-mid holocene
JF  - Quaternary international : the journal of the International Union for Quaternary Research
N2  - We have undertaken a high resolution palaeoclimate reconstruction on radiocarbon dated palaeolake sediments from the Spiti valley, NW Himalaya. This site lies in the climatically sensitive winter westerlies and Indian Summer Monsoon (ISM) transitional regime and provides an opportunity to reconstruct the precipitation seasonality, and extreme precipitation events that are characterised by intensified erosion. The lake sediments reveal distinct lithofacies that provide evidence of changes in depositional environment and climate during early to mid Holocene (8.7-6.1 cal ka BP). We have identified three stages during the period of lake's existence: the Stage I (8.7-7.6 cal ka BP) is marked by lake establishment; Stage II (similar to 7.6-6.8 cal ka BP) by sustained cooler periods and weakened summer monsoon, and Stage III (similar to 6.8-6.1 cal ka BP) by a shift from colder to warmer climate with stronger ISM. We have identified several short term cooler periods at ca. 8.7, 8.5, 8.3 and 7.2-6.9 cal ka BP. Based on an overview of regional climate records we show that there is an abrupt switch in precipitation seasonality ca. 6.8 cal ka BP that is followed by the onset of the intensified monsoon in the NW Himalaya. (C) 2013 Elsevier Ltd and INQUA. All rights reserved.
Y1  - 2013
U6  - https://doi.org/10.1016/j.quaint.2013.08.014
SN  - 1040-6182
VL  - 313
SP  - 74
EP  - 84
PB  - Elsevier
CY  - Oxford
ER  - 
TY  - JOUR
A1  - Wolff, Christian Michael
A1  - Kristen-Jenny, Iris
A1  - Schettler, Georg
A1  - Plessen, Birgit
A1  - Meyer, Hanno
A1  - Dulski, Peter
A1  - Naumann, Rudolf
A1  - Brauer, Achim
A1  - Verschuren, Dirk
A1  - Haug, Gerald H.
T1  - Modern seasonality in Lake Challa (Kenya/Tanzania) and its sedimentary documentation in recent lake sediments
JF  - Limnology and oceanography
N2  - From November 2006 to January 2010, a sediment trap that was cleared monthly was deployed in Lake Challa, a deep stratified freshwater lake on the eastern slope of Mt. Kilimanjaro in southern Kenya. Geochemical data from sediment trap samples were compared with a broad range of limnological and meteorological parameters to characterize the effect of single parameters on productivity and sedimentation processes in the crater basin. During the southern hemisphere summer (November-March), when the water temperature is high and the lake is biologically productive (nondiatom algae), calcite predominated in the sediment trap samples. During the "long rain" season (March-May) a small amount of organic matter and lithogenic material caused by rainfall appeared. This was followed by the cool and windy months of the southern hemisphere winter (June-October) when diatoms were the main component, indicating a diatom bloom initiated by improvement of nutrient availability related to upwelling processes. The sediment trap data support the hypothesis that the light-dark lamination couplets, which are abundant in Lake Challa cores, reflect seasonal delivery to the sediments of diatom-rich particulates during the windy months and diatom-poor material during the wet season. However, interannual and spatial variability in upwelling and productivity patterns, as well as El Nino-Southern Oscillation (ENSO)-related rainfall and drought cycles, exert a strong influence on the magnitude and geochemical composition of particle export to the hypolimnion of Lake Challa.
Y1  - 2014
U6  - https://doi.org/10.4319/lo.2014.59.5.1621
SN  - 0024-3590
SN  - 1939-5590
VL  - 59
IS  - 5
SP  - 1621
EP  - 1636
PB  - Wiley
CY  - Waco
ER  - 
TY  - JOUR
A1  - Neugebauer, Ina
A1  - Brauer, Achim
A1  - Draeger, Nadine
A1  - Dulski, Peter
A1  - Wulf, Sabine
A1  - Plessen, Birgit
A1  - Mingram, Jens
A1  - Herzschuh, Ulrike
A1  - Brande, Arthur
T1  - A Younger Dryas varve chronology from the Rehwiese palaeolake record in NE-Germany
JF  - Quaternary science reviews : the international multidisciplinary research and review journal
N2  - The first 1400-year floating varve chronology for north-eastern Germany covering the late Allered to the early Holocene has been established by microscopic varve counts from the Rehwiese palaeolake sediment record. The Laacher See Tephra (LST), at the base of the studied interval, forms the tephrochronological anchor point. The fine laminations were examined using a combination of micro-facies and mu XRF analyses and are typical of calcite varves, which in this case provide mainly a warm season signal. Two varve types with different sub-layer structures have been distinguished: (I) complex varves consisting of up to four seasonal sub-layers formed during the Allered and early Holocene periods, and, (II) simple two sub-layer type varves only occurring during the Younger Dryas. The precision of the chronology has been improved by varve-to-varve comparison of two independently analyzed sediment profiles based on well-defined micro-marker layers. This has enabled both (1) the precise location of single missing varies in one of the sediment profiles, and, (2) the verification of varve interpolation in disturbed varve intervals in the parallel core. Inter-annual and decadal-scale variability in sediment deposition processes were traced by multi-proxy data series including seasonal layer thickness, high-resolution element scans and total organic and inorganic carbon data at a five-varve resolution. These data support the idea of a two-phase Younger Dryas, with the first interval (12,675-12,275 varve years BP) characterised by a still significant but gradually decreasing warm-season calcite precipitation and a second phase (12,275-11,690 varve years BP) with only weak calcite precipitation. Detailed correlation of these two phases with the Meerfelder Maar record based on the LST isochrone and independent varve counts provides clues about regional differences and seasonal aspects of YD climate change along a transect from a location proximal to the North Atlantic in the west to a more continental site in the east
KW  - Varve chronology
KW  - Micro-fades
KW  - Micro-XRF
KW  - Younger Dryas
KW  - North-eastern Germany
Y1  - 2012
U6  - https://doi.org/10.1016/j.quascirev.2011.12.010
SN  - 0277-3791
VL  - 36
IS  - 10
SP  - 91
EP  - 102
PB  - Elsevier
CY  - Oxford
ER  - 
TY  - JOUR
A1  - Lauterbach, Stefan
A1  - Witt, Roman
A1  - Plessen, Birgit
A1  - Dulski, Peter
A1  - Prasad, Sushma
A1  - Mingram, Jens
A1  - Gleixner, Gerd
A1  - Hettler-Riedel, Sabine
A1  - Stebich, Martina
A1  - Schnetger, Bernhard
A1  - Schwalb, Antje
A1  - Schwarz, Anja
T1  - Climatic imprint of the mid-latitude Westerlies in the Central Tian Shan of Kyrgyzstan and teleconnections to North Atlantic climate variability during the last 6000 years
JF  - The Holocene : an interdisciplinary journal focusing on recent environmental change
N2  - In general, a moderate drying trend is observed in mid-latitude arid Central Asia since the Mid-Holocene, attributed to the progressively weakening influence of the mid-latitude Westerlies on regional climate. However, as the spatio-temporal pattern of this development and the underlying climatic mechanisms are yet not fully understood, new high-resolution paleoclimate records from this region are needed. Within this study, a sediment core from Lake Son Kol (Central Kyrgyzstan) was investigated using sedimentological, (bio) geochemical, isotopic, and palynological analyses, aiming at reconstructing regional climate development during the last 6000 years. Biogeochemical data, mainly reflecting summer moisture conditions, indicate predominantly wet conditions until 4950 cal. yr BP, succeeded by a pronounced dry interval between 4950 and 3900 cal. yr BP. In the following, a return to wet conditions and a subsequent moderate drying trend until present times are observed. This is consistent with other regional paleoclimate records and likely reflects the gradual Late Holocene diminishment of the amount of summer moisture provided by the mid-latitude Westerlies. However, climate impact of the Westerlies was apparently not only restricted to the summer season but also significant during winter as indicated by recurrent episodes of enhanced allochthonous input through snowmelt, occurring before 6000 cal. yr BP and at 5100-4350, 3450-2850, and 1900-1500 cal. yr BP. The distinct similar to 1500year periodicity of these episodes of increased winter precipitation in Central Kyrgyzstan resembles similar cyclicities observed in paleoclimate records around the North Atlantic, likely indicating a hemispheric-scale climatic teleconnection and an impact of North Atlantic Oscillation (NAO) variability in Central Asia.
KW  - Central Asia
KW  - climate
KW  - Holocene
KW  - lake sediments
KW  - mid-latitude Westerlies
KW  - NAO
Y1  - 2014
U6  - https://doi.org/10.1177/0959683614534741
SN  - 0959-6836
SN  - 1477-0911
VL  - 24
IS  - 8
SP  - 970
EP  - 984
PB  - Sage Publ.
CY  - London
ER  - 
TY  - JOUR
A1  - Kalbe, Johannes
A1  - Mischke, Steffen
A1  - Dulski, Peter
A1  - Sharon, Gonen
T1  - The Middle Palaeolithic Nahal Mahanayeem Outlet site, Israel: reconstructing the environment of Late Pleistocene wetlands in the eastern Mediterranean from ostracods
JF  - Journal of archaeological science
N2  - We present ostracod data from the Middle Palaeolithic open air site of Nahal Mahanayeem Outlet (NMO) at the southern edge of the Hula Basin, northern Israel.
 Sediments of two Pleistocene water bodies are exposed at the site. The first one is an archaeologically sterile, light-colored limnic carbonate with an Early Pleistocene age. It contains an ostracod fauna assemblage dominated by Candona neglecta, Candonopsis kingsleii, and Pseudocandona sp., and, in minor abundances, Cypria ophtalmica, Cyprideis sp., Humphcypris sp., Fabaeformiscandona cf. fabaeformis and Ilyocypris sp. These sediments were deposited in a shallow, freshwater to oligohaline lake under stable conditions.
 Sediments of the second water body are silty and dark-colored with a depositional age of 65 ka, belonging to the Late Pleistocene Ashmura Formation. The unit covers a geologically complex topography of tectonically uplifted limnic deposits and a hill-like gravel bar at the site. The most important archaeological layer is situated at its base, containing a lithic assemblage ascribed primarily to the Middle Palaeolithic Mousterian tradition and very well preserved flora and fauna. In the sediments from the archaeological layers, the brackish water ostracod Cyprideis torosa and the foraminifer Ammonia tepida could be identified. In sediments of the Ashmura Formation taken near the site, C. neglecta, Candona angulata, Ilyogpris sp., C kingsleii, Pseudocandona sp., C ophtalmica, Darwinula stevensoni, Trajancypris sp. and Potamogpris smaragdina were found, indicating a freshwater to slightly oligohaline stagnant water body. The ostracod fauna of the NMO site, together with geochemical data, allow us to reconstruct a depositional environment of the margin at a shallow lake with brackish or saline springs nearby during the site's occupation by Middle Palaeolithic humans. 
 Additionally, Candona weltneri, Candona cf. meerfeldiana, C kingsleii, Cyclocypris laevis, C ophtalmica, Cyprideis sp., Fabaeformiscandona cf. fabaeformis, P. smaragdina, Pseudocandona depressa, Trajancypris sp, Zonocypris cf. costata and A. tepida could be recorded for the first time for the Pleistocene limnic strata of the Hula Basin. (C) 2014 Elsevier Ltd. All rights reserved.
KW  - Middle Palaeolithic
KW  - Ostracoda
KW  - Foraminifera
KW  - Gadot Formation
KW  - Ashmura
Y1  - 2015
U6  - https://doi.org/10.1016/j.jas.2014.04.018
SN  - 0305-4403
SN  - 1095-9238
VL  - 54
SP  - 385
EP  - 395
PB  - Elsevier
CY  - London
ER  - 
TY  - GEN
A1  - Lauterbach, Stefan
A1  - Witt, Roman
A1  - Plessen, Birgit
A1  - Dulski, Peter
A1  - Prasad, Sushma
A1  - Mingram, Jens
A1  - Gleixner, Gerd
A1  - Hettler-Riedel, Sabine
A1  - Stebich, Martina
A1  - Schnetger, Bernhard
A1  - Schwalb, Antje
A1  - Schwarz, Anja
T1  - Climatic imprint of the mid-latitude Westerlies in the Central Tian Shan of Kyrgyzstan and teleconnections to North Atlantic climate variability during the last 6000 years
N2  - In general, a moderate drying trend is observed in mid-latitude arid Central Asia since the Mid-Holocene, attributed to the progressively weakening influence of the mid-latitude Westerlies on regional climate. However, as the spatio-temporal pattern of this development and the underlying climatic mechanisms are yet not fully understood, new high-resolution paleoclimate records from this region are needed. Within this study, a sediment core from Lake Son Kol (Central Kyrgyzstan) was investigated using sedimentological, (bio) geochemical, isotopic, and palynological analyses, aiming at reconstructing regional climate development during the last 6000 years. Biogeochemical data, mainly reflecting summer moisture conditions, indicate predominantly wet conditions until 4950 cal. yr BP, succeeded by a pronounced dry interval between 4950 and 3900 cal. yr BP. In the following, a return to wet conditions and a subsequent moderate drying trend until present times are observed. This is consistent with other regional paleoclimate records and likely reflects the gradual Late Holocene diminishment of the amount of summer moisture provided by the mid-latitude Westerlies. However, climate impact of the Westerlies was apparently not only restricted to the summer season but also significant during winter as indicated by recurrent episodes of enhanced allochthonous input through snowmelt, occurring before 6000 cal. yr BP and at 5100-4350, 3450-2850, and 1900-1500 cal. yr BP. The distinct similar to 1500year periodicity of these episodes of increased winter precipitation in Central Kyrgyzstan resembles similar cyclicities observed in paleoclimate records around the North Atlantic, likely indicating a hemispheric-scale climatic teleconnection and an impact of North Atlantic Oscillation (NAO) variability in Central Asia.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 408 
KW  - Central Asia
KW  - climate
KW  - Holocene
KW  - lake sediments
KW  - mid-latitude Westerlies
KW  - NAO
Y1  - 2017
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-404085
ER  - 
TY  - JOUR
A1  - Weber, Michael H.
A1  - Abu-Ayyash, Khalil
A1  - Abueladas, Abdel-Rahman
A1  - Agnon, Amotz
A1  - Alasonati-Tašárová, Zuzana
A1  - Al-Zubi, Hashim
A1  - Babeyko, Andrey
A1  - Bartov, Yuval
A1  - Bauer, Klaus
A1  - Becken, Michael
A1  - Bedrosian, Paul A.
A1  - Ben-Avraham, Zvi
A1  - Bock, Günter
A1  - Bohnhoff, Marco
A1  - Bribach, Jens
A1  - Dulski, Peter
A1  - Ebbing, Joerg
A1  - El-Kelani, Radwan J.
A1  - Foerster, Andrea
A1  - Förster, Hans-Jürgen
A1  - Frieslander, Uri
A1  - Garfunkel, Zvi
A1  - Götze, Hans-Jürgen
A1  - Haak, Volker
A1  - Haberland, Christian
A1  - Hassouneh, Mohammed
A1  - Helwig, Stefan L.
A1  - Hofstetter, Alfons
A1  - Hoffmann-Rothe, Arne
A1  - Jaeckel, Karl-Heinz
A1  - Janssen, Christoph
A1  - Jaser, Darweesh
A1  - Kesten, Dagmar
A1  - Khatib, Mohammed Ghiath
A1  - Kind, Rainer
A1  - Koch, Olaf
A1  - Koulakov, Ivan
A1  - Laske, Maria Gabi
A1  - Maercklin, Nils
T1  - Anatomy of the Dead Sea transform from lithospheric to microscopic scale
N2  - Fault zones are the locations where motion of tectonic plates, often associated with earthquakes, is accommodated. Despite a rapid increase in the understanding of faults in the last decades, our knowledge of their geometry, petrophysical properties, and controlling processes remains incomplete. The central questions addressed here in our study of the Dead Sea Transform (DST) in the Middle East are as follows: (1) What are the structure and kinematics of a large fault zone? (2) What controls its structure and kinematics? (3) How does the DST compare to other plate boundary fault zones? The DST has accommodated a total of 105 km of left-lateral transform motion between the African and Arabian plates since early Miocene (similar to 20 Ma). The DST segment between the Dead Sea and the Red Sea, called the Arava/Araba Fault (AF), is studied here using a multidisciplinary and multiscale approach from the mu m to the plate tectonic scale. We observe that under the DST a narrow, subvertical zone cuts through crust and lithosphere. First, from west to east the crustal thickness increases smoothly from 26 to 39 km, and a subhorizontal lower crustal reflector is detected east of the AF. Second, several faults exist in the upper crust in a 40 km wide zone centered on the AF, but none have kilometer-size zones of decreased seismic velocities or zones of high electrical conductivities in the upper crust expected for large damage zones. Third, the AF is the main branch of the DST system, even though it has accommodated only a part (up to 60 km) of the overall 105 km of sinistral plate motion. Fourth, the AF acts as a barrier to fluids to a depth of 4 km, and the lithology changes abruptly across it. Fifth, in the top few hundred meters of the AF a locally transpressional regime is observed in a 100-300 m wide zone of deformed and displaced material, bordered by subparallel faults forming a positive flower structure. Other segments of the AF have a transtensional character with small pull-aparts along them. The damage zones of the individual faults are only 5-20 m wide at this depth range. Sixth, two areas on the AF show mesoscale to microscale faulting and veining in limestone sequences with faulting depths between 2 and 5 km. Seventh, fluids in the AF are carried downward into the fault zone. Only a minor fraction of fluids is derived from ascending hydrothermal fluids. However, we found that on the kilometer scale the AF does not act as an important fluid conduit. Most of these findings are corroborated using thermomechanical modeling where shear deformation in the upper crust is localized in one or two major faults; at larger depth, shear deformation occurs in a 20-40 km wide zone with a mechanically weak decoupling zone extending subvertically through the entire lithosphere.
Y1  - 2009
UR  - http://www.agu.org/journals/rg/
U6  - https://doi.org/10.1029/2008rg000264
SN  - 8755-1209
ER  - 
TY  - JOUR
A1  - Swierczynski, Tina
A1  - Lauterbach, Stefan
A1  - Dulski, Peter
A1  - Delgado, Jose Miguel Martins
A1  - Merz, Bruno
A1  - Brauer, Achim
T1  - Mid- to late holocene flood frequency changes in the northeastern Alps as recorded in varved sediments of Lake Mondsee (Upper Austria)
JF  - Quaternary science reviews : the international multidisciplinary research and review journal
N2  - Annually laminated (varved) lake sediments with intercalated detrital layers resulting from sedimentary input by runoff events are ideal archives to establish precisely dated records of past extreme runoff events. In this study, the mid- to late Holocene varved sediments of Lake Mondsee (Upper Austria) were analysed by combining sedimentological, geophysical and geochemical methods. This approach allows to distinguish two types of detrital layers related to different types of extreme runoff events (floods and debris flows) and to detect changes in flood activity during the last 7100 years. In total, 271 flood and 47 debris flow layers, deposited during spring and summer, were identified, which cluster in 18 main flood episodes (FE 1-18) with durations of 30-50 years each. These main flood periods occurred during the Neolithic (7100-7050 vyr BP and 6470-4450 vyr BP), the late Bronze Age and the early Iron Age (3300-3250 and 2800-2750 vyr BP), the late Iron Age (2050-2000 vyr BP), throughout the Dark Ages Cold Period (1500-1200 vyr BP), and at the end of the Medieval Warm Period and the Little Ice Age (810-430 vyr BP).
 Summer flood episodes in Lake Mondsee are generally more abundant during the last 1500 years, often coinciding with major advances of Alpine glaciers. Prior to 1500 vyr BP, spring/summer floods and debris flows are generally less frequent, indicating a lower number of intense rainfall events that triggered erosion. In comparison with the increase of late Holocene flood activity in western and northwestern (NW) Europe, commencing already as early as 2800 yr BP, the hydro-meteorological shift in the Lake Mondsee region occurred much later. These time lags in the onset of increased hydrological activity might be either due to regional differences in atmospheric circulation pattern or to the sensitivity of the individual flood archives. The Lake Mondsee sediments represent the first precisely dated and several millennia long summer flood record for the northeastern (NE) Alps, a key region at the climatic boundary of Atlantic, Mediterranean and East European air masses, aiding a better understanding of regional and seasonal peculiarities of flood occurrence under changing climate conditions. (C) 2013 Elsevier Ltd. All rights reserved.
KW  - Varved lake sediments
KW  - Detrital layers
KW  - mu RF
KW  - Microfacies
KW  - Palaeofloods
KW  - Flood frequency
Y1  - 2013
U6  - https://doi.org/10.1016/j.quascirev.2013.08.018
SN  - 0277-3791
VL  - 80
SP  - 78
EP  - 90
PB  - Elsevier
CY  - Oxford
ER  -