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Showing 1 to 20 of 61 for “"lava flows"”.
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Viscoelastic Strain, Viscous Rheology, and Behavior of Experimental Lava Flows
<p>Basaltic pāhoehoe lava flows are prevalent throughout the terrestrial bodies of the solar system. This style of volcanism represents both a predominant resurfacing mechanism of planets and natural satellites and a natural hazard to populations living within volcanically active regions on Earth. …
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Fluvial Response to Intra-Canyon Lava Flows, Owyhee River, Southeastern Oregon
<p>At least six lava flows have entered the Owyhee River Canyon north of Rome, Oregon, since the Pliocene and directly impacted the Owyhee River. The effects on the river of the two youngest lava flows, the West Crater (60–80 ka) and Saddle Butte (> 60–90 ka), are readily apparent. These two lava …
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Characterising subaerial basaltic ‘a‘ā lava flows as potential geothermal reservoirs: Nordeste volcanic complex, Volcanic, São Miguel, Azores
… to providing an analysis of the exposed ‘a‘ā lavas, specifically the cavities within. With a wide range of sizes and origins, the vesicles, segregation vesicles, clinker cavities, drainage cavities and fractures or jointing associated with cooling or vesiculation each provide the sequences …
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Understanding emplacement of rapidly-emplaced volume-limited lava flows from Mount Etna’s 2011-2012 eruption : a multidisciplinary study
… focuses on long-duration cooling-limited lava flows, the short duration and rapid emplacement of many volume-limited flows impedes their analysis. This thesis aims to improve understanding of the emplacement of shortduration volume-limited lava flows by: (1) employing long-range …
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Commonalities in the emplacement of cooling-limited lavas : insights from the 2011-2012 Cordón Caulle rhyolitic eruption
Lava flows pose a risk to infrastructure and communities near many volcanoes. Although the emplacement processes of low-viscosity basaltic lava flows are relatively well studied, the infrequency of silicic eruptions has limited our understanding of the emplacement of high-viscosity rhyolitic lavas. …
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Methods for constructing 3D geological and geophysical models of flood basalt provinces
… include tabular-classic and compound-braided lava flows, intrusions and hyaloclastites. 3D models are constructed for tabular-classic lava flows based on satellite data from Iceland and laser scanning data from a variety of locations. Models for compound-braided lava flows are based on …
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Spreading of viscous fluids and granular materials on slopes
… geophysical and industrial contexts, including lava flows on volcanoes and thin films on coated surfaces. The aim of my research is to provide quantitative insight into these forms of motion and their dependence on effects of the topography, the volume and the rheology of the flowing structure. …
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MAGNETIC DATING OF VESUVIAN LAVAS
… study has been carried out on Vesuvian lava flows emplaced since 79 AD. This involved both palaeodirection and palaeointensity investigations of samples from sites on the W, S and SE slopes of the volcano. Thermal demagnetization of 3 component IRMs, susceptibility measurements and …
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Well log petrophysics and re-interpretation of the exploration target intervals in the southern Walvis basin
… seismic profiles revealed that the volcanics are lava flows with intercalated sediments. The lava flows deposited as a stratified sequence onlappping against an eastern high and herewith their seismic expression is similar to that of a sedimentary succession. Despite the challenges, the basin at …
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The influence of magma supply and eruptive processes on axial morphology, crustal construction and magma chambers
… model for the emplacement of dikes and lava flows with a bimodal distribution of lava flows is required to satisfy geological and geophysical constraints on the construction of the extrusive section. Most dikes are intruded within a narrow zone at the ridge axis. Short flows build up …
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Living in the shadow of Mauna Loa
… activity, the volcano has produced raging lava flows, billowing sulfuricrich clouds, and giant ground cracks, as well as triggered earthquakes, landslides, and even tsunamis. While geologists and emergency managers are concerned about and actively preparing for a future eruption, Hawaii's …
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Deciphering the Signature of Magma Mixing: Examples from the Castle Creek Eruptive Period, Mount St. Helens, Washington
… occasions, the volcano has produced andesite lava flows, and during one short-lived period, basaltic lava flows. This time interval has been termed the Castle Creek eruptive period and occurred between approximately 2500 and 1700 years B.P. The Castle Creek period erupted dacite, andesite and …
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Hydrogeomorphology of Lava Rise Pits in The Laki Lava Field, Southeast Iceland
Lava Rise Pits (LRPs) are found within the Laki lava field in Southern Iceland. LRPs naturally occur in pahoehoe lava flows and form when the flow in lava tubes ceases and collapses. The goal of this study was to better understand the hydrogeomorphology of LRPs during the Fall-winter season. Three …
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Monogenetic volcanism in the western Arabian Peninsula: Insights from Late Quaternary eruptions in northern Harrat Rahat, Kingdom of Saudi Arabia
… The volcanic centres are dominated by lava flows, but explosive eruptions leading to pyroclastic cones and off-cone pyroclastic fall deposits also occurred. Eruptions occurred through point-like, complex, and multiple vents (i.e., along fissures). Lava flows are characterised by a …
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Volcanological studies of Neogene flood basalt groups in eastern Iceland
Flood basalt groups in the Neogene lava piles of eastern Iceland are subject to investigation. The groups form the stratigraphic section above the Reyðarfjörður central volcano up to the Thingmuli central volcano, mapped by the British geologist G. P. L. Walker and his students in the 1950s and …
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An unconformity in the Carolina slate belt of central North Carolina: new evidence for the areal extent of the ca. 600 Ma Virgilina deformation
… the Hyco Formation, consists of intermediate(?) lava flows, pyroclastic and volcaniclastic rocks. Deposition of these units was in a subaqueous environment although some units are indicative of transient subaerial conditions. The Aaron Formation is a volcanic epiclastic sequence composed of …
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