Crossbill (Genus Loxia) evolution in the West Palearctic – a look at the fossil evidence

Ornis Svecica ◽  
1991 ◽  
Vol 1 (1) ◽  
Author(s):  
Tommy Tyrberg
Keyword(s):  
Alternative Hypothesis ◽  
Ice Age ◽  
The West ◽  
Loxia Curvirostra ◽  
Last Glaciation ◽  
Variable Species ◽  
The Alps ◽  
The Mediterranean ◽  
Pine Cones ◽  
South Europe

The systematics of West Palearctic crossbills of Genus Loxia has long been disputed. The Scottish form scotica has been considered a species or a subspecies of either Loxia curvirostra or L. pytyopsittacus. The reason is the size and form of its bill which is intermediate between that of the two species. It feeds on pine cones as do four Mediterranean subspecies which also have larger bills than spruce feeding curvirostra. An examination of about 30 fossil Loxia records reveals that curvirostra type crossbills lived in South Europe and the Near East all through the last glaciation and that pytyopsittacus type crossbills lived in the Alps towards the end of the glaciation. These South European crossbills must have fed on Pine since no other conifers were available, and they must have been isolated from Siberian congeners. With the spread of Pines northwards with the retreat of the ice the crossbills followed. The fossils allow two alternative hypothesis depending on whether the large crossbills in the Alps are considered a species or not. If they were pytyopsittacus this species is rather old and both curvirostra and pytyopsittacus spread northwards at the end of the glaciation. One of the species must have gone extinct in Scotland and South Europe and possible curvirostra must have merged with curvirostra spreading with the Spruce from the east. On the other hand, if the Mediterranean crossbills of the Ice Age represent a single, variable species then all the large-billed forms, pytyopsittacus, scotica and the Mediterranean subspecies are descendants of the old “Pine” crossbills of South Europe.

scholarly journals Mountain torque events in the Mediterranean

2007 ◽  
Vol 12 ◽  
pp. 39-42 ◽  
Author(s):  
J. Egger ◽  
K. P. Hoinka
Keyword(s):  
Rotation Axis ◽  
Potential Temperature ◽  
Western Mediterranean ◽  
The West ◽  
Pressure System ◽  
Temperature Changes ◽  
Low Pressure System ◽  
The Alps ◽  
The Mediterranean ◽  
Upper Level

Abstract. Typical events of torques exerted by the Alps are analysed by correlating flow observations in the Mediterranean with these torques. More specifically, events with positive torques with respect to the "rotation axis" at 90° E, 0° N in fall are selected. A trough forms above the western Mediterranean during such an event with a ridge in the west. A separate low pressure system is induced in the lee of the Alps which moves then eastward with the upper-level trough. A linear forecast equation based on potential temperature changes reveals that this Alpine "lee cyclone" is mainly due to warm air advection east of the trough. Precipitation is discussed as well.

Rates of Deglaciation during the Last Glaciation and Holocene in the Cordillera Vilcanota-Quelccaya Ice Cap Region, Southeastern Perú

2002 ◽  
Vol 57 (3) ◽  
pp. 287-298 ◽  
Author(s):  
Bryan G. Mark ◽  
Geoffrey O. Seltzer ◽  
Donald T. Rodbell ◽  
Adam Y. Goodman
Keyword(s):  
20Th Century ◽  
Little Ice Age ◽  
Ice Age ◽  
Equilibrium Line Altitude ◽  
The West ◽  
Late 20Th Century ◽  
Ice Cap ◽  
Last Glaciation ◽  
Quelccaya Ice Cap ◽  
Over Time

AbstractMoraine chronology is combined with digital topography to model deglacial rates of paleoglacier volumes in both the Huancané Valley on the west side of the Quelccaya Ice Cap and the Upismayo Valley on the northwest side of the Cordillera Vilcanota. The fastest rates of deglaciation (39×10−5 to 114×10−5 km3 yr−1 and 112×10−5 to 247×10−5 km3 yr−1 for each valley, respectively) were calculated for the most recent paleoglaciers, corresponding to the last few centuries. These results are consistent with observations in the Venezuelan Andes showing high rates of deglaciation since the Little Ice Age. These rates also fall within the range of 20th century rates of deglaciation measured on the Quelccaya Ice Cap (29×10−5 to 220×10−5 km3 yr−1, Brecher and Thompson, 1993; Thompson, 2000). These results imply that rates of deglaciation may fluctuate significantly over time and that high rates of deglaciation may not be exclusive to the late 20th century. Equilibrium line altitude (ELA) depressions for the ice volumes of the last glaciation modeled here were computed as 230 m for the Quelccaya Ice Cap and 170 m for the Cordillera Vilcanota. Maximum ELA depressions are lower than previously published: <500 m for the Cordillera Vilcanota and <400 m for the Quelccaya Ice Cap. These lower values could imply a topographic control over paleoglacier extent.

scholarly journals Zur letzten Eiszeit im alpinen und nordeuropäischen Raum

1987 ◽  
Vol 42 (2) ◽  
pp. 93-98 ◽  
Author(s):  
G. Glückert
Keyword(s):  
Fennoscandian Shield ◽  
Ice Age ◽  
Maximum Extent ◽  
Ice Caps ◽  
Last Glaciation ◽  
The Alps ◽  
Last Ice Age ◽  
Marginal Zones

Abstract. On the last Glaciation of the Alps and Fennoscandia. During the Pleistocene the Alps and the Fennoscandian Shield were covered several times with extensive ice caps. During the last Ice Age. the Würm or Weichsel Glaciation, the maximum extent of the glaciers occurred at the end of the Ice Age, as late as 20.000 years ago. The main retreat phases during deglaciation were marked as distinct ice marginal zones and dated between 20,000 and 9,000 BP.

scholarly journals Atmospheric circulation over Europe during the Younger Dryas

2020 ◽  
Vol 6 (50) ◽  
pp. eaba4844
Author(s):  
Brice R. Rea ◽  
Ramón Pellitero ◽  
Matteo Spagnolo ◽  
Philip Hughes ◽  
Susan Ivy-Ochs ◽  
...  
Keyword(s):  
Eastern Mediterranean ◽  
Storm Track ◽  
Younger Dryas ◽  
Jet Stream ◽  
The North ◽  
Blocking High ◽  
Last Glaciation ◽  
The Alps ◽  
Precipitation Anomalies ◽  
Climate Cooling

The Younger Dryas (YD) was a period of rapid climate cooling that occurred at the end of the last glaciation. Here, we present the first palaeoglacier-derived reconstruction of YD precipitation across Europe, determined from 122 reconstructed glaciers and proxy atmospheric temperatures. Positive precipitation anomalies (YD versus modern) are found along much of the western seaboard of Europe and across the Mediterranean. Negative precipitation anomalies occur over the Fennoscandian ice sheet, the North European Plain, and as far south as the Alps. This is consistent with a more southerly and zonal storm track, which is linked to a concomitant southern location of the Polar Frontal Jet Stream, generating cold air outbreaks and enhanced cyclogenesis, especially over the eastern Mediterranean. This atmospheric configuration resembles the modern Scandinavian (SCAND) circulation over Europe (a blocking high pressure over Scandinavia pushing storm tracks south and east), and by analogy, a seasonally varying palaeoprecipitation pattern is interpreted.

scholarly journals New glacier evidence for ice-free summits during the life of the Tyrolean Iceman

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Pascal Bohleber ◽  
Margit Schwikowski ◽  
Martin Stocker-Waldhuber ◽  
Ling Fang ◽  
Andrea Fischer
Keyword(s):  
Elevation Gradient ◽  
Ice Age ◽  
Detailed Knowledge ◽  
New Approach ◽  
Radiocarbon Age ◽  
Alpine Glaciers ◽  
The Alps ◽  
Tyrolean Iceman ◽  
High Elevations ◽  
Age Constraints

AbstractDetailed knowledge of Holocene climate and glaciers dynamics is essential for sustainable development in warming mountain regions. Yet information about Holocene glacier coverage in the Alps before the Little Ice Age stems mostly from studying advances of glacier tongues at lower elevations. Here we present a new approach to reconstructing past glacier low stands and ice-free conditions by assessing and dating the oldest ice preserved at high elevations. A previously unexplored ice dome at Weißseespitze summit (3500 m), near where the “Tyrolean Iceman” was found, offers almost ideal conditions for preserving the original ice formed at the site. The glaciological settings and state-of-the-art micro-radiocarbon age constraints indicate that the summit has been glaciated for about 5900 years. In combination with known maximum ages of other high Alpine glaciers, we present evidence for an elevation gradient of neoglaciation onset. It reveals that in the Alps only the highest elevation sites remained ice-covered throughout the Holocene. Just before the life of the Iceman, high Alpine summits were emerging from nearly ice-free conditions, during the start of a Mid-Holocene neoglaciation. We demonstrate that, under specific circumstances, the old ice at the base of high Alpine glaciers is a sensitive archive of glacier change. However, under current melt rates the archive at Weißseespitze and at similar locations will be lost within the next two decades.

Problems of the Duration of the Eemian Interglacial in Europe North of the Alps

2002 ◽  
Vol 58 (1) ◽  
pp. 45-48 ◽  
Author(s):  
Charles Turner
Keyword(s):  
Mediterranean Region ◽  
Temperate Forest ◽  
Western Europe ◽  
Laminated Sediment ◽  
Annually Laminated Sediment ◽  
The Alps ◽  
The Mediterranean ◽  
Eemian Interglacial

AbstractSuggestions that the duration of the Eemian interglacial was about 11,000 yr, based on annually laminated sediment sequences in Germany, have been challenged in favor of a much longer interval. However, biostratigraphic evidence demonstrates why the Eemian sequences at Grande Pile and Ribains cannot be reliably used for alignment with the marine sequence, as applied by Kukla et al. (2002, this issue) to estimate the duration of this interglacial. The long chronology they propose would imply not just coniferous but, for up to 5000 yr, fully temperate forest in central France coexisting with treeless heath and steppe tundra conditions in northwestern Europe, an unlikely climatic and ecological scenario. The proposal that the Eemian Interglacial in western Europe lasted for 17,000 or even 23,000 yr is rejected. A duration of no more than 13,000 yr is preferred, at least for sites north of the Alps and Pyrenees. The duration of temperate conditions in the Mediterranean region is less certain.

THE BYZANTINE-ISLAMIC CONFLICT IN THE MEDITERRANEAN BASIN, ACCORDING TO PICARD'S OPINION IN HIS BOOK, THE SEA OF THE CALIPHS

2021 ◽  
Vol 3 (4) ◽  
pp. 234-243
Author(s):  
Om Alhana Muhammad Nasr MOHAMMED ◽  
Mabrouka Muhammad Al Ghanay HUSSEIN
Keyword(s):  
Mediterranean Basin ◽  
White Sea ◽  
Historical Narrative ◽  
Narrative Approach ◽  
The White Sea ◽  
The West ◽  
Comparison And Analysis ◽  
The Mediterranean ◽  
The Mediterranean Basin

Throughout the ages, the Mediterranean was considered a Roman lake, and historians and travelers have always considered it as such, and its name changed for them. Some of them called it the Roman Sea, while others called it the White Sea, and no one would have imagined that this Roman lake that Roman ships sailed in, and after that it was inherited by the Byzantines. It will become an Islamic lake, including Henry Perrin of England, followed by Christophe Picard, author of the book Bahr al-Khulafa '. The importance of this research lies in introducing the author of the book, Bahr al-Khulafa ', and highlighting the underlying reason for adhering to the theory that the Mediterranean is a Roman Sea, while the objectives of the research come to reveal the invalidity of the theory that historians adhere to the West, which says that trade in the Mediterranean will collapse with the entry of Muslims into it. The most prominent results of the research were the finding that Picard is only one of the Orientalists, who despite his presence in the countries of the East and his calls that he is an Arabist, not an Orientalist, was unable to deny the accusation of Muslims of piracy in the Mediterranean. The two researchers adopted the historical narrative approach with comparison and analysis whenever the need arises

scholarly journals The AIDOS Project

1970 ◽  
pp. 10
Author(s):  
Lebanese American University
Keyword(s):  
Reproductive Rights ◽  
Arab World ◽  
West Bank ◽  
Gaza Strip ◽  
Mediterranean Area ◽  
International Project ◽  
Information Network ◽  
The West ◽  
West Bank And Gaza ◽  
The Mediterranean

The AIDOS Project: The Institute for Women's Studies in the Arab World, (IWSAW) was selected to take part in an international project aimed at establishing four documentation centers -specialized in women's human, civic, labor and reproductive rights- in fourArab countries: Lebanon, Egypt, Jordan, the West Bank and Gaza Strip. The main objective of the project is to create an information network of women's organizations throughout the Mediterranean area.

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