Mediterranean Sources Research Articles

Pliocene–Pleistocene palaeoclimate reconstruction from Ashalim Cave speleothems, Negev Desert, Israel

Abstract Speleothems from Ashalim Cave, located in the arid central Negev Desert, Israel, were used in a reconstruction of the palaeoclimate of the northern Saharan–Arabian desert margin. The sequence of speleothems is composed of three stratigraphic members: the yellow Pliocene Basal Member, the brown Early Pleistocene Intermediate Member and the thin Middle–Late Pleistocene Young Member. The age of the Basal Member is c. 3.1 Ma and the base of the Intermediate Member is 1.272 ± 0.018 Ma. Two last deposition periods of the Young Member occurred at 221–190 ka (Negev Humid Period (NHP) 2) and 134–114 ka (NHP-1), associated with interglacial marine isotopic stages 7.3–7.1 and 5.5, respectively. NHP-1 and -2 occurred when the African monsoon index was highest in the last 221 ka. The δ 18 O values of the speleothems range between −6.9 and −11.2‰, 2–4‰ less than in the speleothems of central and northern Israel. This may indicate a remote southern tropical source of precipitation, although during NHP-1 and -2 the thickness of the Negev Desert speleothems decreases from north to south, showing a stronger northern Mediterranean source of moisture. The δ 13 C values of the speleothems (3.5 to −8.5‰) show steppe to semi-desert C4 type vegetation. The 87 Sr/ 86 Sr ratios of the speleothems increased from c. 0.7078 in the Pliocene to 0.7082–0.7085 in the Pleistocene, indicating an increasing supply of desert dust and a decrease in host rock weathering.

A long-term perspective on the exploitation of Lipari obsidian in central Mediterranean prehistory

Of the four major island sources of obsidian in the central Mediterranean, Lipari raw materials have the widest distribution, being found at over 200 archaeological sites throughout mainland Italy, southern France, northern Africa, and Sicily. As a means of contextualizing the importance of Lipari obsidian within broader cultural processes, this paper discusses the long-term exploitation of the island's raw materials from the sixth to second millennia BC, in turn emphasizing the reflexive relationship between the movement of Lipari obsidian and the broader circumstances that mediated its use.Over the past 50 years, a large number of studies have been published on obsidian in the central Mediterranean, the majority of which relate to the sourcing of archaeological objects. In total, over 10,000 artifacts have been elementally or visually characterized from well over 400 archaeological sites. Using a newly compiled database of prior obsidian studies, this paper highlights the importance of Lipari obsidian within wider networks of interaction. Through a diachronic overview of the distribution of Lipari obsidian along with a consideration of how these materials were consequently reduced and used, this paper highlights the impact of the spread of Neolithic lifeways on the establishment of large-scale obsidian circulation networks as well as the effects that shifting value regimes associated with the adoption and proliferation of metal technology had on the collapse of long-distance exchange networks. By the second millennium BC, the use of Lipari obsidian becomes a localized phenomenon largely restricted to sites on Sicily and increasingly associated with human burials. While it is easy to explain the continued use of obsidian in these areas as being the result of its ease of procurement, the last vestiges of a dying practice, this paper demonstrates that the situation is slightly more complex.In many ways, the exploitation history of Lipari obsidian mirrors that of other central Mediterranean sources. However, this paper brings to light unique factors that allowed raw materials from a relatively small Aeolian island to become an object of value throughout the entire central Mediterranean.

Mediterranean Outflow Water dynamics during the past ~570 kyr: Regional and global implications

AbstractThe Gulf of Cadiz constitutes a prime area to study teleconnections between the North Atlantic Ocean and climate change in the Mediterranean realm. In particular, the highly saline Mediterranean Outflow Water (MOW) is an important modulator of the North Atlantic salt budget on intermediate water levels. However, our understanding of its paleoceanographic evolution is poorly constrained due to the lack of high‐resolution proxy records that predate the last glacial cycle. Here we present the first continuous and high‐resolution (~ 1 kyr) benthic δ18O and δ13C as well as grain size records from Integrated Ocean Drilling Program Site U1386 representing the last ~570 kyr. We find three distinct phases of MOW variability throughout the Late to Middle Pleistocene at Site U1386 associated with prominent shifts in its composition and flow strength. We attribute this long‐term variability to changes in water mass sourcing of the MOW. Superimposed on the long‐term change in water mass sourcing is the occurrence of distinct and precession paced δ18O enrichment events, which contrast the pattern of global ice volume change as inferred from the global mean δ18O signal (i.e., LR04) but mimics that of the adjacent Mediterranean Sea. We attribute these enrichment events to a profound temperature reduction and salinity increases of the MOW, aligning with similar changes in the Mediterranean source region. These events might further signify ice volume increases as inferred from significant sea level drops recorded in the Red Sea and/or increased influence of North Atlantic intermediate water masses when MOW influence was absent at Site U1386.

The influential role of consensual knowledge in international environmental agreements: negotiating the implementing measures of the Mediterranean Land-Based Sources Protocol (1980)

The generation of consensual scientific knowledge significantly influences the development, evolution and outcome of international environmental negotiations. The impact of consensual science on global environmental policy-making is determined, inter alia, by a number of multidimensional factors. Some of these factors are closely associated with the nature and content of the usable scientific knowledge base. This article introduces the concept of gradated scientific validity and demonstrates how different types and aspects of consensual scientific information affect variously the negotiation process of international environmental agreements. Drawing on the negotiation of the Protocol for the Protection of the Mediterranean against Pollution from Land-Based Sources (1980), it shows that the thorough examination and in-depth analysis of the content and basic characteristics of the available scientific knowledge play a pivotal role in the elaboration and formulation of effective implementing measures of an environmental agreement. It is argued that the prominence of consensual science and subsequently its influence on environmental negotiations are substantially determined by the dynamic role of two interrelated variables of gradated scientific validity: the high or low degree of consensus in relation to the significance and value of the provided scientific information (degree of consensus), and the expanding or narrow scientific consensus on distinct underlying aspects of a negotiating problem, including its causes, extent and consequences (content of consensus). This article indicates that the extensive analysis of the nature, content and distinct characteristics of a consensual knowledge base lays the groundwork for comprehensively understanding the role of consensual science in the negotiation and implementation of an international environmental agreement.

Fish, a Mediterranean source ofn-3 PUFA: benefits do not justify limiting consumption

Fish is an important source of energy, high-quality proteins, fat, vitamins and minerals. Within lipids, n-3 long-chain PUFA (n-3 LC PUFA), mainly EPA and DHA, play an important role in health promotion and disease prevention. In contrast to the potential health benefits of dietary fish intake, certain chemical pollutants, namely heavy metals and some organic compounds, contained in seafood have emerged as an issue of concern, particularly for frequent fish consumers and sensitive groups of populations. The present review summarises the health benefits and risks of fish consumption. n-3 LC-PUFA are key compounds of cell membranes and play an important role in human health from conception through every stage of human development, maturation and ageing. DHA has a major role in the development of brain and retina during fetal development and the first 2 years of life and positively influences neurodevelopment, mainly visual acuity and cognitive functions. n-3 LC-PUFA are also effective in preventing cardiovascular events (mainly stroke and acute myocardial infarction) especially in persons with high cardiovascular risk. By contrast, there is convincing evidence of adverse neurological/neurodevelopmental outcomes in infants and young children associated with methylmercury exposure during fetal development due to maternal fish consumption during pregnancy. Dioxins and polychlorinated biphenyls present in contaminated fish may also develop a risk for both infants and adults. However, for major health outcomes among adults, the vast majority of epidemiological studies have proven that the benefits of fish intake exceed the potential risks with the exception of a few selected species in sensitive populations.

THE IMPACT OF THE CLIMATE CATASTROPHE OF 536–537 AD IN ESTONIA AND NEIGHBOURING AREAS

Introduction In 536-541 AD a short-term and sudden cooling took place in the northern hemisphere which has caught the attention of researchers only quite recently. In 1983, Richard Stothers and Michael Rampino published a list of volcanic eruptions prior to 630 AD known from historical sources (Stothers & Rampino 1983). Their list included a veil of dust or dry fog that darkened the sky for almost a year in 536-537 AD and caused crop failure. Dendrochronologist Mike Baillie found physical evidence of the event studying the tree rings of Irish oak (Baillie 1994). During the last decades, numerous publications (e.g. Randsborg 1997; Axboe 1999; 2001a; 2001b; Baillie 1999; Keys 1999; Gunn 2000; Hoilund Nielsen 2006; Graslund 2008; Graslund & Price 2012; Arrhenius 2013) have discussed the historical significance and impact of the 536-537 event as well as its archaeological manifestations and written sources. The emergence of this new research topic is due to recent advancements in climate reconstructions based on natural science. Having access to much higher-resolution climate records makes it possible to discuss the demographic, economic, and cultural impacts of climate change more precisely (Widgren 2012, 126). The event in question appears clearly in the growth rings of trees in the northern hemisphere, namely in the common oak (Quercus robur) and families of pine (Pinus). Tree rings show abnormally little growth in 536 and the following years. A similar pattern has been found in tree rings from 540 in the southern hemisphere, for example in southern Chile and Argentina (Baillie 1999; 2007; Gunn 2000; Jones 2000; Young 2000 and citations therein). Tree rings of the northern hemisphere show that growth was hampered in two periods. After recovery a new, even sharper drop emerged in 540-541 (D'Arrigo et al. 2001, 240). According to tree rings, extraordinarily cold weather continued in the northern hemisphere until the year 545 (Graslund & Price 2012, 430 and citations therein). Traces of the event can be found in ice cores from Greenland and Antarctica. The earliest studies referred to the high sulphuric acid content of ice deposits in Greenland from around 540 which indicate the volcanic origin of the event (see Stothers & Rampino 1983; Stothers 1999). Later researchers have also found evidence of substantial sulphate deposits in ice layers from Greenland and Antarctica, supporting the notion of volcanic dust (e.g. Traufetter et al. 2004; Larsen et al. 2008; Ferris et al. 2011). Most scientists who have studied the causes of the event of 536 have concluded that it was caused by an immense volcanic eruption in the tropical zone of Earth (see Stothers & Rampino 1983; Stothers 1999; Larsen et al. 2008). Several volcanoes and places have been proposed (see Stothers 1984; Keys 1999; Wohletz 2000). The most convincing evidence so far refers to the Tierra Blanca Joven eruption of the Ilopango caldera in central El Salvador (Dull et al. 2001; 2010; Oppenheimer 2011, 254 ff.). Others believe that a comet or a meteorite explosion caused the event (Baillie 1999; 2007; Rigby et al. 2004). Magnetite and silicate spherules found from the ice layers of 536-537 in Greenland support this alternative explanation (Abbott et al. 2008). Similar sphelures have been found in northern Australia from a supposed metorite crater in the Gulf of Carpentaria (Abbott et al. 2008; Subt et al. 2010). Thus, natural scientists have not agreed on what caused the climate anomaly of 536-537. Nevertheless, according to tree growth rings it was the worst shock to the ecosystem within the last 2000 years (Baillie 2007, 106). Antti Arjava (2006) has studied written evidence from Mediterranean sources of the extraordinary event of 536-537. In several of these sources it appears that a darkening of the sun was observable in the Mediterranean region during more than a year. Bishop Michael the Syrian writes in his 12th century chronicle, quoting the 6th century ecclesiastical historian John of Ephesos: Each day it shone for about four hours, and still this light was only a feeble shadow. …

Magdalenian societies in the Massif Central (France) : archaeological and paleohistorical perspectives on the Long-Term (16.5-11.5 ky BP)

The chronology of the most extensive Late Pleistocene glaciation in the eastern Pyrenees is now well established, but climatic variations during the subsequent Last Glacial-to-Interglacial Transition (LGIT) are much less well documented. The aim of this research is to fill that gap. We present a new series of 22 10Be exposure ages from a sequence of moraines in the upper Ariège catchment, and update 64 previously published exposure ages from seven other valleys. Based on (i) geomorphological maps of successive generations of ice-marginal deposits and (ii) their age distributions, followed by (iii) glaciological modeling to infer corresponding mass-balance gradients and equilibrium line altitudes (ELAs), we reconstruct glacier behaviour in the eastern Pyrenees during the LGIT and retrieve paleoclimatic parameters for each glacial stillstand. Results document rapid deglaciation involving four relative stillstands, with an ELA rise of ∼410 m and increases in temperature and precipitation of ∼4 °C and ∼40%, respectively, between ∼18 ka (Greenland Stadial GS-2.1b) and ∼14.5 ka (Greenland Interstadial GI-1). A cold and dry environment prevailed from ∼18 ka onward, and deglaciation was almost complete by GI-1. Only small glaciers persisted as late as ∼12.3 ka in cirques where local conditions allowed it. These patterns are compatible with a transient Polar Front Jet Stream repositioning to latitudes of 40–42°N between 18 and 16 ka, with Westerlies-dominated circulation not yet feeding precipitation to the mountain belt abundantly from the northwest, and outbursts of polar air meeting with cool sea waters in the western Mediterranean mostly suppressing precipitation from Mediterranean sources.

IMPACT OF INSTANTANEOUS CONTROLLED PRESSURE PROP (DIC) TECHNOLOGY ON EXTRACTION OF TOTAL PHENOLS OF MOROCCAN SALVIA OFFICINALIS

The main objective of this study was to intensify the extraction of total phenols from Salvia officinalis L. using instant controlled pressure drop (DIC) as a texturing pre-treatment. The effect of solvent type on Total Phenolic Content (TPC) was also studied. TPC was determined using spectrophotometric Folin-Ciocalteau method and external calibration with Gallic acid. The obtained results showed that water was the most efficient solvent to extract total phenols from Salvia officinalis L. Moreover, texturing and expansion by DIC pretreatment had a great impact on polyphenol yields and revealed greater extraction kinetics. Likewise, drying kinetics of DIC-treated sage was enhanced compared to the raw material. DIC-assisted extraction can be considered as a promising technology to use in the case of the Moroccan Salvia officinalis L. as an important Mediterranean source of natural phenols.

Climatic factors controlling chemical and isotopic characteristics of precipitation in Syria

AbstractThe chemical and isotopic composition of monthly composite rain samples collected at 13 meteoric stations in Syria during two hydrological cycles from 1991 to 1993 have been measured. The chemical analysis of the samples revealed at a number of stations pollution due to industry and sand storms. The temporal and spatial variation of the isotopic composition has been found to be comparable with one of the neighbouring countries such as Jordan and others. The average weighted oxygen‐18 and deuterium values are − 7·5 and − 39·11‰, respectively, and the deuterium excess is 21‰ . The individual isotope values can be divided into two groups. One group is represented by winter precipitation and fits closely the Mediterranean Meteorological Water Line (MMWL). Thus, for winter precipitation, condensation of Mediterranean water vapour appears to be the dominating isotope fractionation process. The other group represents spring precipitation and is spread along an evaporation line below the MMWL, thus indicating the influence of sub‐cloud evaporation. The d‐excess has been found to be lower in the north of Syria (19·9‰ at Tartous, 18·1‰ at Jarablous) than in the south of the country (23·4‰ at Sweida, 24·1‰ at Izra) where Mediterranean air mass dominates. The d‐excess of precipitation in neighbouring countries is also close to the average value of the eastern Mediterranean basin of 22‰ , e.g. for Jordan the value is 23‰ , which signifies that Mediterranean water vapour is, for all these countries, the dominant source of precipitation. The tritium content of precipitation was found to increase with distance from the coast (5·3 TU at coastal station Tartous, 8·8 TU at continental station Palmyra). Low tritium content and high d‐excess at coastal stations clearly indicate a Mediterranean air moisture source. Copyright © 2010 John Wiley & Sons, Ltd.

Paleoclimatic implications of the spatial patterns of modern and LGM European land-snail shell δ 18O

The oxygen isotopic composition of land-snail shells may provide insight into the source region and trajectory of precipitation. Last glacial maximum (LGM) gastropod shells were sampled from loess from Belgium to Serbia and modern land-snail shells both record δ 18O values between 0‰ and − 5‰. There are significant differences in mean fossil shell δ 18O between sites but not among genera at a single location. Therefore, we group δ 18O values from different genera together to map the spatial distribution of δ 18O in shell carbonate. Shell δ 18O values reflect the spatial variation in the isotopic composition of precipitation and incorporate the snails' preferential sampling of precipitation during the warm season. Modern shell δ 18O decreases in Europe along a N–S gradient from the North Sea inland toward the Alps. Modern observed data of isotopes in precipitation (GNIP) demonstrate a similar trend for low-altitude sites. LGM shell δ 18O data show a different gradient with δ 18O declining toward the ENE, implying a mid-Atlantic source due to increased sea ice and a possible southern displacement of the westerly jet stream. Balkan LGM samples show the influence of a Mediterranean source, with δ 18O values decreasing northward.

Obsidian sources in highland Yemen and their relevance to archaeological research in the Red Sea region

The Red Sea and surrounding area formed through dynamic uplift and rifting of Afro-Arabia, and associated volcanism (both oceanic and continental in character). As a result, volcanic landforms and products are widespread and play a vital role in the natural and cultural landscapes of humans occupying the highlands and lowlands on both sides of the Red Sea. Archaeologists have suggested for some time that Afro-Arabian trade in obsidian had its roots in the prehistoric period and that the region was very likely the source of an abundance of obsidian artefacts found as far afield as Egypt, the Persian Gulf and Mesopotamia, and which do not match the well-known Anatolian, Transcaucasian or Mediterranean sources. Nonetheless, the southern Red Sea is one of the few obsidian-rich regions exploited in antiquity that has been barely investigated. In this paper, we highlight new geochemical analyses (carried out by LA-ICP-MS) of obsidian sources in Southern Arabia and beyond, that enhance our knowledge of obsidian exploitation from as early as the Neolithic period, and which enable us to evaluate the role that highland Yemen obsidian sources played in prehistoric long-distance trade. In addition, we present new evidence for explosive volcanic eruptions that likely affected the highland populations of Yemen in the 4th millennium BC.

Community impacts of anthropogenic disturbance: natural enemies exploit multiple routes in pursuit of invading herbivore hosts

BackgroundBiological invasions provide a window on the process of community assembly. In particular, tracking natural enemy recruitment to invading hosts can reveal the relative roles of co-evolution (including local adaptation) and ecological sorting. We use molecular data to examine colonisation of northern Europe by the parasitoid Megastigmus stigmatizans following invasions of its herbivorous oak gallwasp hosts from the Balkans. Local host adaptation predicts that invading gallwasp populations will have been tracked primarily by sympatric Balkan populations of M. stigmatizans (Host Pursuit Hypothesis). Alternatively, ecological sorting allows parasitoid recruitment from geographically distinct populations with no recent experience of the invading hosts (Host Shift Hypothesis). Finally, we test for long-term persistence of parasitoids introduced via human trade of their hosts' galls (Introduction Hypothesis).ResultsPolymorphism diagnostic of different southern refugial regions was present in both mitochondrial and nuclear microsatellite markers, allowing us to identify the origins of northern European invaded range M. stigmatizans populations. As with their hosts, some invaded range populations showed genetic variation diagnostic of Balkan sources, supporting the Host Pursuit Hypothesis. In contrast, other invading populations had an Iberian origin, unlike their hosts in northern Europe, supporting the Host Shift Hypothesis. Finally, both British and Italian M. stigmatizans populations show signatures compatible with the Introduction Hypothesis from eastern Mediterranean sources.ConclusionsThese data reveal the continental scale of multi-trophic impacts of anthropogenic disturbance and highlight the fact that herbivores and their natural enemies may face very different constraints on range expansion. The ability of natural enemies to exploit ecologically-similar hosts with which they have had no historical association supports a major role for ecological sorting processes in the recent assembly of these communities. The multitude of origins of invading natural enemy populations in this study emphasises the diversity of mechanisms requiring consideration when predicting consequences of other biological invasions or biological control introductions.

A major and long-term Pliocene intensification of the Mediterranean outflow, 3.5-3.3 Ma ago

Largely continuous millennial-scale records of benthic delta O-18, Mg/Ca-based temperature, and salinity variations in bottom waters were obtained from Deep Sea Drilling Project (DSDP) Site 548 (East Atlantic continental margin near Ireland, 1250 m water depth) for the period 3.7-3.0 Ma ago. High epsilon(Nd) values of -10.7 to -9 show that this site monitored changes in Mediterranean Outflow Water (MOW) throughout the mid-Pliocene. Bottom water variability at Ocean Drilling Progam (ODP) Site 978 (Alboran Sea, 1930 m water depth) provides a complementary record of MOW composition near its West Mediterranean source. Both sites show a singular and persistent rise in bottom water salinities by 0.7-1.4 psu, and in densities by similar to 1 kg m(-3) from 3.5 to 3.3 Ma ago, which is matched by an similar to 3 degrees C increase in bottom water temperature at Site 548. This event suggests the onset of strongly enhanced deep-water convection in the Mediterranean Sea and a related increase in MOW flow as a result of major aridification in the Mediterranean source region. In harmony with model suggestions, the enhanced MOW flow has possibly intensified Upper North Atlantic Deep Water formation.

On the effects of parameterized Mediterranean overflow on North Atlantic ocean circulation and climate

A parameterized Mediterranean overflow, based on the marginal sea boundary condition of [Price, J., Yang, J., 1998. Marginal sea overflows for climate simulations. In: Chassignet, E.P., Verron, J., (Eds.), Ocean Modeling and Parameterization, Kluwer Academic, pp. 155–170], has been implemented in the ocean component of the Community Climate System Model to represent exchanges through the Strait of Gibraltar, associated entrainment and intrusion of overflow product water into the Atlantic. Previously, in coarse resolution model versions with a closed Strait, this physics has been either missing in uncoupled configurations or only partially and unphysically treated as a surface salt exchange when fully coupled. Parameter choices are evaluated by comparing climatologically forced solutions to observations and process model results. The two major criteria satisfied by the implementation in a fully coupled climate model and an uncoupled global ocean model are stable solutions and projection of the overflow signal across the Atlantic basin at about 1000 m depth. Both of these configurations are low resolution, and in both the transports of inflow, source and entrainment water are all within the range of observed estimates, but there is too little product water. This bias is attributed to inadequate modeling of water masses in the Mediterranean source region. Nevertheless, the properties of the product water differ little from observed estimates and both the uncoupled and coupled models develop a Mediterranean salt tongue that spreads west and south from the Strait with a signature reminiscent of the observed hydrography. The improvements relative to either blocking the Strait, or excavating a too wide channel are presented. In the coupled solution, the impact of the improved overflow physics on the global climate is minimal, with North Atlantic sea surface temperatures and heat fluxes changing generally by less than 1 °C and 15 W m −2, respectively. However, there is interesting spatial variability in the coupling strength, which ranges between ±20 W m −2 °C −1 in the coupled case.

Mediterranean outflow strengthening during northern hemisphere coolings: A salt source for the glacial Atlantic?

High-resolution grain size and magnetic susceptibility records from the eastern Gulf of Cadiz (site MD99-2339; 1170 m water depth) reveal contourites formed by the Mediterranean Outflow (MOW) during the last 47 kyr BP. Oscillations in the MOW's intensity occurred in phase with Greenland temperature variations with a stronger outflow during northern hemisphere coolings such as Dansgaard-Oeschger stadials, Heinrich events, and the Younger Dryas. Benthic δ 13C data implies the Western Mediterranean Deep Water as one of the main sources feeding the outflow current, while differential changes in the properties of the Mediterranean source and entrained North Atlantic Central Water largely control the MOW's strength. Detailed studies for Heinrich events 1, 4 and 5 show that the flow strength peaked only when subtropical surface waters prevailed in the eastern Gulf of Cadiz, while incursions of icebergs and subpolar surface water were not favorable for the MOW's intensification. As the MOW was strong when the Atlantic's thermohaline circulation (THC) was weakened, the heat and salt injected by the MOW into the intermediate North Atlantic waters might have preconditioned the THC to switch from the stadial to the interstadial mode.

The Mystery Cloud of 536 CE in the Mediterranean Sources

The Mystery Cloud of 536 CE in the Mediterranean Sources

A Lagrangian Analysis of the Atmospheric Branch of the Global Water Cycle. Part I: Method Description, Validation, and Demonstration for the August 2002 Flooding in Central Europe

Understanding and quantifying the relationships between evaporation of water in one region, precipitation in another, and the transport processes connecting them, is one of the key problems in hydrometeorology. However, to date few methods exist that are suitable for establishing these relationships. In this paper, a new Lagrangian technique is described that builds on methods that have been developed for investigating source‐receptor relationships for air pollutants. It is based on meteorological analysis data and a particle dispersion model and uses a Lagrangian analog to the Eulerian budget method to diagnose the surface moisture flux. Because of its Lagrangian nature, regions of net evaporation are connected by trajectories with regions of net precipitation, and these trajectories can be used to examine how the two are related. The method is shown to yield estimates for the global distribution of the annual mean surface freshwater flux that are equally accurate as those obtained with the Eulerian budget method. It is then applied in a case study of an extreme precipitation event that occurred in central Europe in August 2002 and led to floodings with return periods of 100 to 300 yr in some river catchments. Again it is shown that the moisture fluxes obtained with the Lagrangian and Eulerian method, respectively, agree well with each other, and both agree well with observed precipitation patterns and shortrange precipitation forecasts. Then the new method is used to determine where the water that became precipitation during the flooding event has evaporated. It is found that in addition to a strong Mediterranean source, much of the water evaporated from land. The strong extra evaporation over land was likely due to a wet spell the weeks before that left soils saturated with water in large parts of Europe and flooded in some smaller regions. It appears that precipitation forecasts suffered from predicting too little evaporation in these regions.

Raman micro‐spectroscopy of western Mediterranean obsidian glass: one step towards provenance studies?

AbstractThis paper presents the first results of the Raman characterization of obsidians from the western Mediterranean. About 40 geological samples, from the islands of Lipari, Palmarola, Pantelleria and Sardinia, representative of the seven archaeologically significant obsidian sources, were analysed. Apart from the general shape of the spectra, which characterize three islands, a detailed treatment of the stretching massif part was performed to obtain quantitative discriminating parameters. The combination of these factors seems to provide a complete discrimination of all archaeologically significant western Mediterranean sources. These sources have provided raw material of Meso‐ and Neolithic artefacts distributed around the Tyrrhenian basin and nowadays provide key evidence of ancient exchange networks. Because some alternatives to classical geochemical fingerprinting are currently being sought, Raman spectroscopy could be a complementary or even alternative technique in provenance studies of archaeological obsidians. Copyright © 2004 John Wiley & Sons, Ltd.

SEM-EDS microanalysis of microphenocrysts of Mediterranean obsidians : a preliminary approach to source discrimination

SEM-EDS non-destructive analysis allows the source discrimination of the various microphenocrysts in obsidian rocks of the Mediterranean. Samples of six Mediterranean sources, Monte Arci (Sardinia), Palmarola, Lipari, Pantelleria, Gyali and Melos were studied using SEM-EDS non-destructive techniques in order to obtain a data base of their microphenocryst content. The results demonstrate that provenance of an obsidian can be distinguished on the basis of its petrography, in particular by quantitative analyses of Fe-Mg microphenocrysts; this information is particularly useful when coupled with data obtained by other non-destructive techniques such as glass microanalysis of artefacts (Acquafredda et al. , 1999). Such investigations, carried out by SEM, an analytical technique relatively accessible to geoarchaeologists, are relatively rapid, effective and above all non-destructive.

Mediterranean moisture source for an early-Holocene humid period in the northern Red Sea.

Paleosalinity and terrigenous sediment input changes reconstructed on two sediment cores from the northernmost Red Sea were used to infer hydrological changes at the southern margin of the Mediterranean climate zone during the Holocene. Between approximately 9.25 and 7.25 thousand years ago, about 3 per thousand reduced surface water salinities and enhanced fluvial sediment input suggest substantially higher rainfall and freshwater runoff, which thereafter decreased to modern values. The northern Red Sea humid interval is best explained by enhancement and southward extension of rainfall from Mediterranean sources, possibly involving strengthened early-Holocene Arctic Oscillation patterns and a regional monsoon-type circulation induced by increased land-sea temperature contrasts. We conclude that Afro-Asian monsoonal rains did not cross the subtropical desert zone during the early to mid-Holocene.