Individual and community behavioral responses to natural disasters     

Berrebi  Claude  Karlinsky  Ariel  Yonah  Hanan 《Natural Hazards》2021,105(2):1541-1569

Natural Hazards - How do people and communities respond to catastrophes? A natural disaster is a type of external, quasi-random and unexpected catastrophic shock that generates psychological,...  相似文献   

Hafnium isotopic variations in East Atlantic intraplate volcanism     

Jörg Geldmacher  Kaj Hoernle  Barry B. Hanan  Janne Blichert-Toft  F. Hauff  James B. Gill  Hans-Ulrich Schmincke 《Contributions to Mineralogy and Petrology》2011,162(1):21-36

The broad belt of intraplate volcanism in the East Atlantic between 25° and 37° N is proposed to have formed by two adjacent hotspot tracks (the Madeira and Canary tracks) that possess systematically different isotopic signatures reflecting different mantle source compositions. To test this model, Hf isotope ratios from volcanic rocks from all individual islands and all major seamounts are presented in this study. In comparison with published Nd isotope variations (6 εNd units), ¹⁷⁶Hf/¹⁷⁷Hf ratios span a much larger range (14 εHf units). Samples from the proposed Madeira hotspot track have the most radiogenic Hf isotopic compositions (¹⁷⁶Hf/¹⁷⁷Hf_m up to 0.283335), extending across the entire field for central Atlantic MORB. They form a relatively narrow, elongated trend on the Nd vs. Hf isotope diagram (stretching over > 10 εHf units) between a depleted N-MORB-like endmember and a moderately enriched composition located on, or slightly below, the Nd–Hf mantle array, which overlaps the proposed “C” mantle component of Hanan and Graham (1996). In contrast, all samples from the Canary hotspot track plot below the mantle array (¹⁷⁶Hf/¹⁷⁷Hf_m = 0.282943–0.283067) and form a much denser cluster with less compositional variation (~4 εHf units). The cluster falls between (1) a low Hf isotope HIMU-like endmember, (2) a more depleted composition, and (3) the moderately enriched end of the Madeira trend. The new Hf isotope data confirm the general geochemical distinction of the Canary and Madeira domains in the East Atlantic. Both domains, however, seem to share a common, moderately enriched endmember that has “C”-like isotope compositions and is believed to represent subducted, <1-Ga-old oceanic lithosphere (oceanic crust and possibly minor sediment addition). The lower ¹⁷⁶Hf/¹⁷⁷Hf ratio of the enriched, HIMU-like Canary domain endmember indicates the contribution of oceanic lithosphere with somewhat older recycling ages of ≥1 Ga.  相似文献   

Source components and magmatic processes in the genesis of Miocene to Quaternary lavas in western Turkey: constraints from HSE distribution and Hf–Pb–Os isotopes     

Ercan Aldanmaz  Megan Pickard  Thomas Meisel  Şafak Altunkaynak  Kaan Sayıt  Pınar Şen  Barry B. Hanan  Tanya Furman 《Contributions to Mineralogy and Petrology》2015,169(2):1-20

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Metamorphic grade and gradient from white K-micas of Na-mica bearing sedimentary rocks in the Mosquito Creek Basin,East Pilbara Craton,Western Australia     

Hanan J. Kisch  Wouter Nijman 《Precambrian Research》2010,176(1-4):11-26

Shales and phyllites from the turbidite sequences of the 2.9 Ga Mosquito Creek Formation of the East Pilbara, Western Australia contain varying amounts of paragonite and mixed Na–K micas (MNKMs), the 0 0 l X-ray diffraction reflections of which are unresolved from the 10-Å reflections, and only partly resolved from the 5-Å reflections of white K-mica (WKM). The Kübler index (‘crystallinity’), the full width at half maximum (FWHM) of the WKM, obtained from these composite reflections by applying a three-peak deconvolution procedure, reveals a metamorphic zoning of the Mosquito Creek Formation. The highest, “epimetamorphic”, grade occurs in the — largely Na-mica free — southern part, with lower, medium- to high-anchimetamorphic, grades in the central part, notably in a WSW-ENE anticlinal zone extending from Nullagine to the Blue Spec Mine. The Na-mica free metasediments of the Glen Herring Shale of the Fortescue Group, overlying the Mosquito Creek Formation to the W, show only a slightly lower metamorphic grade. The low b₀ lattice parameter of the WKMs indicates a very low metamorphic P/T gradient. The Na-mica bearing metasediments of the Mosquito Creek Formation correspond to a kaolinite-bearing protolith, strongly Al-enriched and K-depleted with respect to the presumably granitic-tonalitic source rock.  相似文献   

Delineation of paleolakes in the Sinai Peninsula,Egypt, using remote sensing and GIS     

A. Gaber  E. Ghoneim  F. Khalaf  F. El-Baz 《Journal of Arid Environments》2009,73(1):127-134

Well-stratified lacustrine deposits of clay, silt, and marl occur within the rugged mountainous triangle of igneous and metamorphic rocks of Sinai Peninsula, Egypt. These deposits occur only in two sites along Wadi Feiran channel (Feiran and El-Tarfa Oases), where very dense acidic dykes intersect their stream courses. Such dykes played an important role in damming water from torrential rainfall during the humid period to form lakes. The SRTM (90 m) data and high-resolution images (IKONOS) have been utilized to reconstruct the paleolakes in terms of shape, size and water volume. Results show that lake deposits are located where acidic dykes cross narrow channel of high sinuosity. At their former heights, the dykes dammed the surface runoff, thus, three local freshwater paleolakes formed behind them. GIS analysis shows that the largest of these paleolakes was formed in the area of Feiran Oasis. Two other smaller paleolakes were formed at El-Tarfa Oasis due to the presence of two pronounced acidic dykes.These lake deposits were derived mainly from El-Tih Plateau via Wadi El-Akhdar. Another source of these deposits could have been a thin sedimentary cap over the weathered granites northeast of Feiran basin.  相似文献   

Earthquake risk assessment of Alexandria,Egypt     

Ahmed Badawy  Hanan Gaber  Hamza Ibrahim 《Journal of Seismology》2015,19(1):159-170

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Crustal structure of Iraq from receiver functions and surface wave dispersion: implications for understanding the deformation history of the Arabian–Eurasian collision     

Rengin Gök  Hanan Mahdi  Haydar Al-Shukri  Arthur J. Rodgers 《Geophysical Journal International》2008,172(3):1179-1187

We report the crustal structure for two locations in Iraq estimated by joint inversion of P -wave receiver functions (RFs) and surface (Rayleigh) wave group velocity dispersion. RFs were computed from teleseismic recordings at two temporary broad-band seismic stations located in Mosul (MSL) in the Zagros Fold Belt and Baghdad (BHD) in the Mesopotamian Foredeep. Group velocity dispersion curves at the sites were derived from continental-scale tomography. The inversion results show that the crustal thicknesses are 39 km at MSL and 43 km at BHD. We observe a strong Ps _Moho at BHD consistent with a sharp Moho discontinuity. However, at MSL we observe a weak Ps _Moho suggesting a transitional Moho where crustal thickening is likely to be occurring in the deep crust. Both sites reveal low velocity surface layers consistent with sedimentary thickness of about 3 km at station MSL and 7 km at BHD and agreeing well with the previous reports. Ignoring the sediments, the crystalline crustal velocities and thicknesses are remarkably similar at both stations. The similarity of crustal structure suggests that the crust of the northeastern proto-Arabian Platform was uniform before subsidence and deposition of the sediments in the Cenozoic. If crystalline crustal structure is uniform across the northern Arabian Platform then crustal thickness variations in the Zagros Fold Belt and Thrust Zone should reveal the history of deformation and crustal shortening in the Arabian–Eurasian collision zone and not reflect pre-existing crustal thickness variations in the Arabian Plate.  相似文献   

Erratum to: Lead in drinking water and human blood in Riyadh City, Saudi Arabia     

Abdulaziz M. Al-Othman  Zeid A. Al-Othman  Gaber E. El-Desoky  Mourad A. M. Aboul-Soud  Mohamed A. Habila  John P. Giesy 《Arabian Journal of Geosciences》2013,6(10):4091-4091

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Early pleistocene lake deposits and Lower Paleolithic finds in Nahal (wadi) Zihor, Southern Negev desert, Israel     

Hanan Ginat  Ezra Zilberman  Idit Saragusti 《Quaternary Research》2003,59(3):445-458

An Early Pleistocene fluvio-lacustrine sequence from the extremely arid southern Negev desert, Israel, indicates that climatic conditions during that period were humid enough to support the formation of a lake (Lake Zihor) there. The lacustrine sediments were deposited in a tectonic valley that developed along the Zihor tectonic line after the deposition of the Pliocene Arava Formation. They intercalate with fluvial sediments that contain several horizons of reddish calcic paleosols. The lacustrine sequence comprises three sedimentary cycles. Each starts with a dark clay layer overlain by a white limestone unit, both of which contain abundant freshwater fauna, and terminates with a green detrital limestone that contains only one type of brackish-water ostracod. The top of each green limestone unit is characterized by pedogenic features and microrelief, indicating desiccation of the lake and soil development. Isotope data support the hypothesis that the white limestone was deposited in an open, freshwater lake. The incision of the present channel of Nahal (wadi) Zihor in the lacustrine sediments is manifested by a series of rock-cut and fluvial terraces (Q1–Q4) capped by gypsic-salic soils, which reflect the onset of the present, extremely arid climate. Over 100 find-spots and larger occurrences of prehistoric artifacts assigned to the Lower Paleolithic were discovered near Lake Zihor. On the basis of techno-typological and stratigraphic considerations, these assemblages are divided into two groups, the first of which may be contemporaneous with the lake, while the second is found mainly on the younger Q1 and Q2 terraces. It is estimated that the lake existed for more than 100,000 years. The climate during this period was probably semiarid, but water budget calculations suggest that, in addition to surface runoff, seepage of groundwater along the Zihor Line contributed a considerable amount of water to the lake.  相似文献   

SrNdPb geochemical morphology between 10° and 17°N on the Mid-Atlantic Ridge: A new MORB isotope signature     

Laure Dosso  Barry B. Hanan  Henri Bougault  Jean-Guy Schilling  Jean-Louis Joron 《Earth and Planetary Science Letters》1991,106(1-4)

Basalts dredged along the Mid-Atlantic Ridge axis between 10°N and 17°N have been studied for their trace element characteristics [1]. To give complementary information on mantle source history and magma genesis, these samples have been analysed for their SrNdPb isotopic compositions. There is a good correlation between the structure of the ridge axis which shows a topographic anomaly centered around 14°N and hygromagmaphile element ratios such as Rb/Sr, (Nb/Zr)_N or Sm/Nd as well as isotopic ratios plotted as a function of latitude. The samples coming from the 14°N topographic high show new MORB SrNd isotopic characteristics which pictured in a classical mantle array diagram, put their representative points close to HIMU sources of ocean islands such as St. Helena, Tubuaïand Mangaia. The 14°N mantle source presents geochemical characteristics which indicate mantle differentiation processes and a mantle history that are more distinct than so far envisaged from typical MORB data. Pb data indicates that the 14°N mantle source cannot be the result of binary mixing between a depleted mantle and a HIMU-type source. Rather, the enriched endmember could itself be a mixture of Walvis-like and HIMU-like materials. The geochimical observations presented favour the model of an incipient ridge-centered plume, in agreement with [1].  相似文献