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141.
AbstractUsing observations from 688 debris flows, we analyse the hydrologic and landscape characteristics that influenced debris-flow initiation mechanisms and locations in a watershed that had been partially burned by the 2012 Whitewater-Baldy Complex Fire in the Gila Mountains, southern New Mexico. Debris flows can initiate due to different processes. Slopes can fail as discrete landslides and then become fluidized and move downstream as debris flows (landslide initiated) or progressive bulking of sediment from a distributed area can become channelized and concentrated as it moves downslope (runoff generated). In this study, we have an unusual opportunity to investigate both types of debris-flow initiation mechanisms in our observations of debris flows, triggered by an exceptional rainstorm in the autumn of 2013. Additionally, we compare our observations with those of a dataset of 1138 debris flows in the Colorado Front Range, triggered during the same weather system. We found that runoff-generated debris flows dominated in burn areas, and runoff required to start these flows could be well characterized by the Shields stress. Landslide-initiated debris flows were dominant in unburned areas. Debris-flow densities were tied to total rainfall and precipitation intensities. Like the observations in the Colorado Front Range, debris-flow initiation locations were found primarily in areas of relatively sparse vegetation on south-facing slopes between 25 and 40°, and with upslope contributing areas less than 1000 m2. In terms of preferential locations for debris-flow initiations, 2013 vegetation coverage, approximated by Green–Red Vegetation Index metrics, proved to be more influential than the 2012 burn-severity designation. The uniformity of observations between our study area and those in the Colorado Front Range indicate that the underlying hydrologic and landscape patterns of the debris-flow initiation locations documented in these studies could be applicable to the wider southwest and Rocky Mountain regions. © 2019 John Wiley & Sons, Ltd. 相似文献
142.
Oryński Szymon Klityński Wojciech Neska Anne Ślęzak Katarzyna 《Studia Geophysica et Geodaetica》2019,63(2):273-289
Studia Geophysica et Geodaetica - A fundamental tectonic boundary between the Precambrian East European Craton (EEC) and the younger Phanerozoic mountain belts of Europe runs through Poland.... 相似文献
143.
Dumas Dylan Gramoullé Anthony Guérin Charles-Antoine Molcard Anne Ourmières Yann Zakardjian Bruno 《Ocean Dynamics》2020,70(12):1485-1503
Ocean Dynamics - The high-frequency radar coastal network in Toulon operates in multistatic mode for the monitoring of the ocean circulation in the Northwestern Mediterranean Sea. With 2... 相似文献
144.
Guillaume Siron Lukas Baumgartner Anne‐Sophie Bouvier Benita Putlitz Torsten Vennemann 《Geostandards and Geoanalytical Research》2017,41(2):243-253
Five new biotite reference materials were calibrated at the SwissSIMS laboratory (University of Lausanne) for oxygen isotope determination by secondary ion mass spectrometry (SIMS) and are available to the scientific community. The oxygen isotope composition of the biotites, UNIL_B1 to B5, was determined by laser‐heating fluorination to be 11.4 ± 0.11‰, 8.6 ± 0.15‰, 6.1 ± 0.04‰, 7.1 ± 0.05‰ and 7.6 ± 0.04‰, respectively. SIMS analyses on spots smaller than 20 μm gave a measurement repeatability of 0.3‰ (2 standard deviation, 2s). The matrix effect due to solid solution in natural biotite could be expressed as a linear function of XMg and XF for biotite. No effect was found for different crystallographic orientations. SIMS analysis allows the oxygen isotope composition of biotite to be measured with a measurement uncertainty of 0.3–0.4‰ (2s) for biotites with similar major element compositions. A measurement uncertainty of 0.5‰ (2s) is realistic when F poor biotites (lower than 0.2% m/m oxides) within the compositional range of XMg of 0.3–0.9 were compared from different sessions. The linear correlation with F content offers a reasonable working curve for F‐rich biotites, but additional reference materials are needed to confirm the model. 相似文献
145.
Anne Claude Naki Akçar Susan Ivy-Ochs Fritz Schlunegger Philippe Rentzel Christine Pümpin Dmitry Tikhomirov Peter W. Kubik Christof Vockenhuber Andreas Dehnert Meinert Rahn Christian Schlüchter 《Swiss Journal of Geoscience》2017,110(3):793-809
The Quaternary stratigraphy of the Alpine Foreland consists of distinct terrace levels, which have been assigned to four morphostratigraphic units: Höhere (Higher) Deckenschotter, Tiefere (Lower) Deckenschotter, Hochterrasse (High Terrace) and Niederterrasse (Lower Terrace). Here, we focus on the terrace gravels at Hohle Gasse, SSE of Pratteln near Basel, which are mapped as Tiefere Deckenschotter. Petrographic and morphometric data established from clasts allowed to infer the transport mechanisms and sources of the gravels. Sedimentological analyses indicate that the gravels were transported by a braided river and deposited in a distal glaciofluvial setting. In addition, it can be shown that the majority of the clasts display multiple reworking and only a minority maintained a distinct glaciofluvial shape. Cosmogenic multi-isotope dating using 10Be and 36Cl allowed direct dating of the sediments at the study site. A depth-profile age of \(2 70_{ - 1 90}^{ + 8 30}\) ka for 10Be was achieved for the deposits at Hohle Gasse. Unfortunately, no age could be modelled from the 36Cl concentrations as the blank correction was too high. Furthermore, this age proves that the studied terrace level should be assigned to the morphostratigraphic unit Hochterrasse. 相似文献
146.
A workflow for simultaneous joint PP‐PS prestack inversion of data from the Schiehallion field on the United Kingdom Continental Shelf is presented and discussed. The main challenge, describing reasonable PS to PP data registration before any prestack or joint PP‐PS inversion, was overcome thanks to a two‐stage process addressing the signal envelope, then working directly on the seismic data to estimate appropriate time‐variant time‐shift volumes. We evaluated the benefits of including PS along with PP prestack seismic data in a joint inversion process to improve the estimated elastic property quality and also to enable estimation of density compared with other prestack and post‐stack inversion approaches. While the estimated acoustic impedance exhibited a similar quality independent of the inversion used (PP post‐stack, PP prestack or joint PP‐PS prestack inversion) the shear impedance estimation was noticeably improved by the joint PP‐PS prestack inversion when compared to the PP prestack inversion. Finally, the density estimated from joint PP and PS prestack data demonstrated an overall good quality, even where not well‐controlled. The main outcome of this study was that despite several data‐related limitations, inverting jointly correctly processed PP and PS data sets brought extra value for reservoir delineation as opposed to PP‐only or post‐stack inversion. 相似文献
147.
Anne Marie de Grosbois 《Environmental Geology》2009,57(7):1693-1698
148.
149.
Brunet Morgane Moretti Laurent Le Friant Anne Mangeney Anne Fernández Nieto Enrique Domingo Bouchut Francois 《Natural Hazards》2017,85(2):1189-1208
Natural Hazards - In November 2015, China government announced that the national carbon emissions trading market is expected to start in 2017. Carbon emission trading system is a raising concern... 相似文献
150.