A non-hydrostatic model for the numerical study of landslide-generated waves     

Pengfei Si  Jordan Aaron  Scott McDougall  Ji Lu  Xiping Yu  Nicholas J. Roberts  John J. Clague 《Landslides》2018,15(4):711-726

This paper proposes and demonstrates a two-layer depth-averaged model with non-hydrostatic pressure correction to simulate landslide-generated waves. Landslide (lower layer) and water (upper layer) motions are governed by the general shallow water equations derived from mass and momentum conservation laws. The landslide motion and wave generation/propagation are separately formulated, but they form a coupled system. Our model combines some features of the landslide analysis model DAN3D and the tsunami analysis model COMCOT and adds a non-hydrostatic pressure correction. We use the new model to simulate a 2007 rock avalanche-generated wave event at Chehalis Lake, British Columbia, Canada. The model results match both the observed distribution of the rock avalanche deposit in the lake and the wave run-up trimline along the shoreline. Sensitivity analyses demonstrate the importance of accounting for the non-hydrostatic dynamic pressure at the landslide-water interface, as well as the influence of the internal strength of the landslide on the size of the generated waves. Finally, we compare the numerical results of landslide-generated waves simulated with frictional and Voellmy rheologies. Similar maximum wave run-ups can be obtained using the two different rheologies, but the frictional model better reproduces the known limit of the rock avalanche deposit and is thus considered to yield the best overall results in this particular case.  相似文献   

Broadband seismic source data acquisition and processing to delineate iron oxide deposits in the Blötberget mine-central Sweden     

Tatiana Pertuz  Alireza Malehmir  Jordan Bos  Bojan Brodic  Yinshuai Ding  Richard de Kunder  Paul Marsden 《Geophysical Prospecting》2022,70(1):79-94

A prototype electromagnetic vibrator, referred to here as E-Vib, was upgraded and developed for broadband hardrock and mineral exploration seismic surveys. We selected the iron oxide mine in Blötberget, central Sweden, for a test site in 2019 for the newly developed E-Vib because of the availability of earlier seismic datasets (from 2015 to 2016) for verification of its performance for hardrock imaging purposes. The two-dimensional data acquisition consisted of a fixed geometry with 550 receiver locations spaced at every 5 m, employing both cabled and wireless seismic recorders, along an approximately 2.7 km long profile. The E-Vib operated at every second receiver station (i.e. 10 m spacing) with a linear sweep of 2–180 Hz and with a peak force of 7 kN. The processing workflow took advantage of the broadband signal generated by the E-Vib in this challenging hardrock environment with varying ground conditions. The processed seismic section shows a set of reflections associated with the known iron oxide mineralization and a major crosscutting reflection interpreted to be from a fault system likely to be crosscutting the mineralization. The broadband source data acquisition and subsequent processing helped to improve signal quality and resolution in comparison with the earlier workflows and data where a drophammer seismic source was used as the seismic source. These results suggest new possibilities for the E-Vib source for improved targeting in hardrock geological settings.  相似文献   

Rockfall susceptibility and runout in the Valley of the Kings     

Marija  Lukovic  Martin  Ziegler  Jordan  Aaron  Matthew  Perras 《Natural Hazards》2022,110(1):451-485

Natural Hazards - The UNESCO world heritage site Valley of the Kings or Wadi el-Moluk (???? ??????) near Luxor, Egypt, hosts unique...  相似文献   

Recharge response and kinematics of an unusual earthflow in Liechtenstein     

Aaron  Jordan  Loew  Simon  Forrer  Markus 《Landslides》2021,18(7):2383-2401

Landslides - Understanding landslide behavior over medium and long timescales is crucial for predicting landslide hazard and constructing accurate landscape evolution models. The behavior of...  相似文献   

Strong slope-aspect control of regolith thickness by bedrock foliation     

Jordan D. Leone  W. Steven Holbrook  Clifford S. Riebe  Jon Chorover  Ty P.A. Ferré  Bradley J. Carr  Russell P. Callahan 《地球表面变化过程与地形》2020,45(12):2998-3010

The porous near-surface layer of the Earth's crust – the critical zone – constitutes a vital reservoir of water for ecosystems, provides baseflow to streams, guides recharge to deep aquifers, filters contaminants from groundwater, and regulates the long-term evolution of landscapes. Recent work suggests that the controls on regolith thickness include climate, tectonics, lithology, and vegetation. However, the relative paucity of observations of regolith structure and properties at landscape scales means that theoretical models of critical zone structure are incompletely tested. Here we present seismic refraction and electrical resistivity surveys that thoroughly characterize subsurface structure in a small catchment in the Santa Catalina Mountains, Arizona, USA, where slope-aspect effects on regolith structure are expected based on differences in vegetation. Our results show a stark contrast in physical properties and inferred regolith thickness on opposing slopes, but in the opposite sense of that expected from environmental models and observed vegetation patterns. Although vegetation (as expressed by normalized difference vegetation index [NDVI]) is denser on the north-facing slope, regolith on the south-facing slope is four times thicker (as indicated by lower seismic velocities and resistivities). This contrast cannot be explained by variations in topographic stress or conventional hillslope morphology models. Instead, regolith thickness appears to be controlled by metamorphic foliation: regolith is thicker where foliation dips into the topography, and thinner where foliation is nearly parallel to the surface. We hypothesize that, in this catchment, hydraulic conductivity and infiltration capacity control weathering: infiltration is hindered and regolith is thin where foliation is parallel to the surface topography, whereas water infiltrates deeper and regolith is thicker where foliation intersects topography at a substantial angle. These results suggest that bedrock foliation, and perhaps by extension sedimentary layering, can control regolith thickness and must be accounted for in models of critical zone development. © 2020 John Wiley & Sons, Ltd.  相似文献   

Cenozoic landscape evolution of the Kruger National Park as derived from cosmogenic nuclide analyses          下载免费PDF全文

Christoph Glotzbach  Alexander Paape  Jussi Baade  Bastian Reinwarth  Kate Rowntree  Jordan Miller 《地学学报》2016,28(5):316-322

In contrast to active tectonic settings, little is known about the potential feedback between surface processes and climate change in tectonically inactive cratonic regions. Here, we studied the driving forces of erosion and landscape evolution in the Kruger National Park in South Africa using cosmogenic nuclide dating. ¹⁰Be‐derived catchment‐wide erosion rates (~2 and ~10 mm ka^?1) are similar in magnitude to erosion and rock uplift elsewhere in South Africa, suggesting that (1) rock uplift is solely the isostatic response to erosion and (2) the first‐order topography is likely of Cretaceous age. The topographic maturity is promoted by widespread exposure of rocks resistant to erosion. Our data, however, suggest that local variations in rock resistance lead to transient landscape changes, with local increases in relief and erosion rates.  相似文献   

Trophic Resource Overlap Between Small Elasmobranchs and Sympatric Teleosts in Mid-Atlantic Bight Nearshore Habitats     

Ryan Jordan Woodland  David H. Secor  Madeline E. Wedge 《Estuaries and Coasts》2011,34(2):391-404

Small, abundant elasmobranchs use shallow marine areas (<20 m depth) of the US Middle Atlantic coast as nurseries and adult foraging habitat, an area also used by a diverse assemblage of economically important juvenile and adult teleost species. Specimens of three small elasmobranch species (smooth dogfish Mustelus canis, clearnose skate Raja eglanteria, and bullnose ray Myliobatis freminvillii) were collected in August 2007 and 2008 from a study area of ∼150 km², extending 22 km south from Ocean City, Maryland, USA (38° 19′ N) and offshore from 5- to 20-m depth. Stomach contents indicated that fish were part of the diets of smooth dogfish and clearnose skate at a level comparable with sympatric piscivorous teleosts. However, stable isotope data suggest that piscivory is likely an opportunistic foraging behavior in this habitat. Studied elasmobranchs were secondary-tertiary consumers with diets composed primarily of decapod crustaceans, fish, and mollusks. There was significant overlap in diet composition, spatial distribution, and diel stomach fullness patterns between clearnose skate, southern kingfish Menticirrhus americanus (teleost) and, to a lesser extent, smooth dogfish. Despite this evidence for piscivory, their relatively low densities suggest that predation by these elasmobranchs is unlikely to affect teleost populations in shallow coastal ocean habitats. If shared prey were to become scarce, then competitive interactions are possible.  相似文献   

Understanding Place Attachment to the County in the American Great Plains          下载免费PDF全文

Jeffrey S. Smith  Jordan M. McAlister 《Geographical review》2015,105(2):178-198

The American Great Plains is a region dominated by a flat, treeless, semiarid environment that has challenged population settlement for over 140 years. As railroad companies successfully attracted pioneers to settle the land, state governments established hundreds of counties. Following Jeffersonian ideals, many of the counties were small in area so they could better serve the local agricultural‐based population. When states established these counties, they envisioned that the population would continue to grow and the Great Plains would become the breadbasket of North America. Unfortunately that did not materialize. A succession of hardships combined with serious environmental constraints has discouraged large‐scale settlement in the region. Many counties reached their maximum population in the early 1900s and their totals have decreased ever since (in some counties by as much as 60 percent to 80 percent). This has led a number of government officials to consider consolidating counties much like school districts have been combined. Using Logan and Gove counties in western Kansas as a case study, our purpose is to understand how attached people are to the county in which they live. Employing multiple methods, we gathered information about how different segments of the population regard their local county. We learned that changing computer technology and the Internet has the biggest impact on peoples' attachment to the county seat.  相似文献   

The fate of waste in Hawaii: Technology assessment and solid waste planning in Hawaii, 1968–78          下载免费PDF全文

Jordan P. Howell 《Singapore journal of tropical geography》2015,36(1):67-82

In this article I consider the initial period of solid waste management planning in the US state of Hawaii. The State encountered a number of economic and ecological controversies during its solid waste management planning, a process that was prompted by the US Environmental Protection Agency. Some issues, like project financing, were common across the US, while others, such as the potential of waste materials to reduce reliance on imported food and materials, were more unique to Hawaii. The controversies from this initial planning period were never quite fully resolved; as they lingered, they were interpreted differently across the Islands. Based on a close reading of government, advocacy group, waste industry and news media documents, I examine the controversies over solid waste management of the time and consider how the ‘dual nature’ of waste in Hawaii—simultaneously an ecological threat and (potential) economic input—shaped the adoption of solid waste management systems there. This article adds to an expanding literature examining infrastructure in environmental and technology histories.  相似文献   

Erratum to: Variability of gas composition and flux intensity in natural marine hydrocarbon seeps     

Jordan F. Clark  Libe Washburn  Katherine Schwager Emery 《Geo-Marine Letters》2010,30(3-4):389-389

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