A spatial approach to forest‐management optimization: linking GIS and multiple objective genetic algorithms     

E. I. Ducheyne  R. R. De Wulf  B. De Baets 《International journal of geographical information science》2013,27(8):917-928

Forest‐management decision‐support systems are largely monolithic structures. Spatial details are left out during the optimization process and are elaborated during the operational planning. This might produce misleading results and plans that are impossible to implement. In this paper, a forest‐management spatial decision‐support systems is presented, in which spatial formulation needed for wildlife models is included during the optimization process. To this end, a multiple‐objective genetic algorithm is combined with a geographical information system. An online spatial evaluation of the objective functions is made possible. This is illustrated by a pilot study in Kirkhill forest, Aberdeen.  相似文献   

Detection of the Askja AD 1875 cryptotephra in Latvia,Eastern Europe          下载免费PDF全文

Normunds Stivrins  Sabine Wulf  Stefan Wastegård  Ewa M. Lind  Tiiu Alliksaar  Mariusz Gałka  Thorbjørn Joest Andersen  Atko Heinsalu  Heikki Seppä  Siim Veski 《第四纪科学杂志》2016,31(5):437-441

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The youngest volcanic eruptions in East‐Central Europe—new findings from the Ciomadul lava dome complex,East Carpathians,Romania          下载免费PDF全文

D. Karátson  D. Veres  S. Wulf  R. Gertisser  E. Magyari  M. Bormann 《Geology Today》2017,33(2):60-65

Violent explosive eruptions occurred between c. 51 and 29 thousand years ago—during the Last Glacial Maximum in East‐Central Europe—at the picturesque volcano of Ciomadul, located at the southernmost tip of the Inner Carpathian Volcanic Range in Romania. Field volcanology, glass geochemistry of tephra, radiocarbon and optically stimulated luminescene dating, along with coring the lacustrine infill of the two explosive craters of Ciomadul (St Ana and Mohos), constrain the last volcanic activity to three subsequent eruptive stages. The explosivity was due to the silicic composition of the magma producing Plinian‐style eruptions, and the interaction of magma with the underlying, water‐rich rocks resulting in violent phreatomagmatic outbursts. Tephra (volcanic ash) from these eruptions are interbedded with contemporaneous loess deposits, which form thick sequences in the vicinity of the volcano. Moreover, tephra layers are also preserved in the older Mohos crater infill, providing an important archive for palaeoclimate studies. Identifying the final phreatomagmatic eruption of Ciomadul at c. 29.6 ka, which shaped the present‐day landform of the 1600‐m‐wide St Ana explosion crater, we were able to correlate related tephra deposits as far as 350 km from the source within a thick loess‐palaeosol sequence at the Dniester Delta in Roxolany, Ukraine. A refined tephrostratigraphy, based on a number of newly found exposures in the Ciomadul surrounding region as well as correlation with the distal terrestrial and marine (e.g. Black Sea) volcano‐sedimentary record, is expected from ongoing studies.  相似文献   

Detection of the historical Askja ad 1875 and modern Icelandic cryptotephras in varved lake sediments – results from a first systematic search in northern Poland     

MaŁgorzata Kinder  Sabine Wulf  Oona Appelt 《第四纪科学杂志》2021,36(1):1-7

Volcanic ash can disperse thousands of kilometres from the source volcano and provide valuable chronostratigraphic markers for palaeoclimate studies. We present new cryptotephra findings of historical and modern Icelandic eruptions in annually laminated lacustrine sediment records from several sites within a 570 km SW–NE transect across northern Poland. Sediments from the two lakes Wąsoskie and Szurpiły contain glass shards originating from the Plinian Askja ad 1875 eruption and showing bimodal, rhyolitic and dacitic affinities. A further cryptotephra finding in Lake Lubińskie suggests a potential origin from the Hekla ad 1845 eruption. These new findings extend the tephra dispersal map towards the south-east and provide valuable isochrons for the synchronisation of palaeoclimate proxy data at the termination of the Little Ice Age in central eastern Europe. Very low glass concentrations of modern cryptotephra in Lake Wąsoskie were potentially correlated with the Eyjafjallajökull ad 2010 eruption. Further findings in the uppermost sediments of lakes Szurpiły and Żabińskie in north-eastern Poland tentatively suggest other sources from either the Hekla and/or Kamchatkan volcanoes.  相似文献   

Experimental distinction of elements with similar atomic number in (Pb,Bi)-sulfosalts     

Dr. R. Wulf 《Mineralogy and Petrology》1995,52(3-4):187-196

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Felsic fire-fountaining beneath Archean seas: pyroclastic deposits of the 2730 Ma Hunter Mine Group, Quebec, Canada     

Wulf Mueller  James D.L. White 《Journal of Volcanology and Geothermal Research》1992,54(1-2)

The lapilli tuff breccias (LTB-1 and LTB-2) of the Archean Hunter Mine Group in the south-central part of the Abitibi greenstone belt are inferred to be the product of subaqueous lava fountaining. Intercalated sub-wave base iron-formations, interstratified turbiditic tuffs, the absence of wave-induced sedimentary structures, and the stratigraphic position of lapilli tuff breccias beneath basaltic komatiites, support this contention. A complete eruptive sequence shows a tripartite division into (a) massive breccia, (b) stratified lapilli tuff, and (c) turbiditic tuff-lapilli tuff division. The massive breccia division is characterized by clusters of isolated and compressed irregular-shaped clasts inferred to be deposited directly from the hot magmatic lava fountain. Abundant vesicular pyroclasts with a vesicle content of up to 60% exhibit locally coalescing vesicles indicating bubble nucleation prior to eruption. The prevalence of irregular to amoeboid clast shapes suggests transport from the vent in a steamy-rich, high-density current to the site under a self-generated steam cupola. Ubiquitous subequant lapilli-size pyroclasts of the stratified lapilli tuff division suggest that significant ingress of water into the fountain changed the prevalent fragmentation process from magmatic to hydrovolcanic. The turbiditic tuff-lapilli tuff division composed of pumice, lithic fragments and vitric ash is envisaged to have formed by gravitational collapse of a subaqueous turbulent eruptive plume. This type of eruptive mechanism constituted a minor but important process of volcanic construction on the ocean floor during the Archean, and possibly during incipient arc and backarc formation in modern day settings.  相似文献   

Does temperature influence the spawning time, recruitment and distribution of flatfish via its influence on the rate of gonadal maturation?     

Uwe Lange  Wulf Greve 《Ocean Dynamics》1997,49(2-3):251-263

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Paleogeographic and paleotectonic response to magmatic processes: a case history from the Archean sequence in the Chibougamau area,Quebec     

Erich Dimroth  Michel Rochelau  Wulf Mueller  Paul Archer  Harold Brisson  Gabriel Fortin  Marc Jutras  Christian Lefebvre  Mathieu Piché  Pierre Pilote  Pierre Simoneau 《International Journal of Earth Sciences》1985,74(1):11-32

The Chibougamau area, Québec, is characteristic of the internal zone of the Archean Abitibi Orogenic Belt. The paleogeographic, paleotectonic and magmatic history of the Archean sequence in the Chibougamau area is subdivided into three stages.In the first stage a submarine volcanic chain formed mainly by the effusion of submarine lava flows composed of primitive, potash-poor, tholeiitic basalt. The volcanic chain gradually grew to sea level. In the second stage, volcanic islands emerged and grew. Mainly pyroclastic eruptions of strongly differentiated, calc-alkaline andesite and dacite concentrated on the volcanic islands, whereas effusion of basalt continued at first in the surrounding basin. A felsic volcaniclastic apron was deposited around the volcanic islands. In the third stage, the volcanic islands were uplifted and were eroded to the level of their subvolcanic plutons. The debris derived from this volcanic-plutonic terrain was deposited in downfaulted marine and continental basins. The contemporaneous volcanism was shoshonitic.The first paleogeographic stage is interpreted as the growth of an immature island arc. During the second stage, the island arc became mature and its crust was thickened by accretion of plutonic material. The third stage is a period of back-arc extension.

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Zusammenfassung Das Gebiet von Chibougamau, Québec, ist characteristisch für die interne Zone des Archaischen Abitibi Orogens. Man kann seine paleogeographische, paleotectonische und magmatische Geschichte in drei Phasen gliedern.Eine submarine Vulkankette formte sich in der ersten Phase, hauptsächlich durch Effusion von submarinen Lavaergüssen aus primitivem, kaliarmen, tholeiitischem Basalt. Die Vulkankette wuchs langsam bis zum Meeresspiegel. Vulkanische Inseln bildeten sich und wuchsen während der zweiten paleogeographischen Phase. Vorwiegend pyroklastische Eruptionen von stark differenzierten, kalk-alkalischem Andesit und Dazit konzentrierten sich mehr und mehr auf den Inselvulkanen, während die Effusion von Basalt zunächst in den Becken noch stattfand. Ein Mantel aus felsitischen vulkanoklastischen Gesteinen wurde um die Inselvulkane abgelagert. Die dritte Phase begann mit einer Hebung der Inselvulkane und mit ihrer Erosion bis zum Niveau ihrer subvulkanischen Plutone. Der Detritus dieses vulkanisch-plutonischen Geländes wurde in marinen und kontinentalen Verwerfungsbecken abgelagert. Der gleichalte Vulkanismus ist shoshonitisch.Wir deuten die erste paleogeographische Phase als Wachstumsphase eines primitven Inselbogens. Während der zweiten Phase reifte der Inselbogen und seine Kruste verdickte sich durch Akkretion plutonischen Materials. Die dritte Phase ist eine Periode der Dehnung im Hinterland eines Inselbogens.

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Résumé La région de Chibougamau, Québec, est caractéristique de la zone interne de la ceinture orogénique archéenne de l'Abitibi. Son évolution paléogéographique, paléotectonique et magmatique se subdivise en trois phases.Lors de la première phase paléogéographique, une chaîne sous-marine de volcans se formait, essentiellement par l'émission de coulées de lave composée de basalte primitif, hypopotassique, tholéiitique. Graduellement cette chaîne volcanique s'élevait jusqu'au niveau de la mer. A la phase suivante, des îles volcaniques émergeaient et croissaient. Des éruptions essentiellement pyroclastiques d'andésites et de dacites calco-alcalines et fortement différenciées se concentraient sur les îles tandis que l'effusion de laves basaltiques continuaient dans le bassin. Un manteau de roches volcaniclastiques felsiques se déposait autour des îles volcaniques. Lors de la troisième phase, les îles volcaniques furent soulevées et furent érodées jusqu'au niveau des masses plutoniques sub-volcaniques. Le débris de ce terrain volcano-plutonique fut déposé dans des bassins de faille marins et continentaux. Des shoshonites dominaient le volcanisme contemporain.Nous interprétons la première phase paléogéographique comme une phase de croissance d'un arc insulaire immature. Lors de la deuxième phase, 1'arc insulaire devenait mature et sa croûte s'epaissît par accrétion de matériel plutoni-que. Enfin, la troisième phase est une période d'extension en arrière d'un arc insulaire.

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Inland navigation in Europe — its tasks and its problems     

D. Wulf 《GeoJournal》1977,1(2):25-31

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Cryptotephras in the Lateglacial ICDP Dead Sea sediment record and their implications for chronology     

Ina Neugebauer  Daniela Müller  Markus J. Schwab  Simon Blockley  Christine S. Lane  Sabine Wulf  Oona Appelt  Achim Brauer 《Boreas: An International Journal of Quaternary Research》2021,50(3):844-861

Due to a lack of visible tephras in the Dead Sea record, this unique palaeoenvironmental archive is largely unconnected to the well-established Mediterranean tephrostratigraphy. Here we present first results of the ongoing search for cryptotephras in the International Continental Drilling Program (ICDP) sediment core from the deep Dead Sea basin. This study focusses on the Lateglacial (~15–11.4 cal. ka BP), when Lake Lisan – the precursor of the Dead Sea – shrank from its glacial highstand to the Holocene low levels. We developed a glass shard separation protocol and counting procedure that is adapted to the extreme salinity and sediment recycling of the Dead Sea. Cryptotephra is abundant in the Dead Sea record (up to ~100 shards cm^-3), but often glasses are physically and/or chemically altered. Six glass samples from five tephra horizons reveal a heterogeneous geochemical composition, with mainly rhyolitic and some trachytic glasses potentially sourced from Italian, Aegean and Anatolian volcanoes. Most shards likely originate from the eastern Anatolian volcanic province and can be correlated using major element analyses with tephra deposits from swarm eruptions of the Süphan Volcano ~13 ka BP and with ashes from Nemrut Volcano, presumably the Lake Van V-16 volcanic layer at ~13.8 ka BP. In addition to glasses that match the TM-10-1 from Lago Grande di Monticchio (15 820±790 cal. a BP) tentatively correlated with the St. Angelo Tuff of Ischia, we further identified a cryptotephra with glass analyses which are chemically identical with those of the PhT1 tephra in the Philippon peat record (13.9–10.5 ka BP), and also a compositional match for the glass analyses of the Santorini Cape Riva Tephra (Y-2 marine tephra, 22 024±642 cal. a BP). These first results demonstrate the great potential of cryptotephrochronology in the Dead Sea record for improving its chronology and connecting the Levantine region to the Mediterranean tephra framework.  相似文献