Late Quaternary rapid talus dissection and debris flow deposition on an alluvial fan in Syria

CATENA ◽  
2004 ◽  
Vol 55 (2) ◽  
pp. 125-140 ◽  
Author(s):  
Takashi Oguchi ◽  
Chiaki T. Oguchi
Keyword(s):  
Debris Flow ◽  
Late Quaternary ◽  
Alluvial Fan

scholarly journals Pleistocene Stratigraphy of the Athabasca River Valley Region, Rocky Mountains, Alberta

2007 ◽  
Vol 49 (3) ◽  
pp. 381-399 ◽  
Author(s):  
Victor M. Levson ◽  
Nathaniel W. Rutter
Keyword(s):  
Debris Flow ◽  
Rocky Mountains ◽  
Late Quaternary ◽  
Rocky Mountain ◽  
River Valley ◽  
Alluvial Fan ◽  
Front Range ◽  
Stratigraphic Sequence ◽  
Athabasca River ◽  
Lithostratigraphic Units

ABSTRACTThe Pleistocene stratigraphy of the central Canadian Rocky Mountains is described from a region where few studies of Late Quaternary deposits have been conducted. Six informal lithostratigraphic units are recognized from newly mapped exposures in Jasper National Park. The oldest deposits are interpreted as paleofan deposits (Unit 1) and they are overlain by glaciofluvial gravels and sands (Unit 2), glaciolacustrine sediments (Unit 3) and by a glacigenic diamicton sequence (Unit 4) that includes basal till, supraglacial deposits and ice-marginal debris flow sediments. Proximal glaciofluvial gravels, debris flow deposits and minor glaciolacustrine sediments (Unit 5) and paragiacial fan deposits and loess (Unit 6) cap the stratigraphic sequence. Limited chronologic control suggests that nonglacial fluvial and alluvial fan sedimentation began prior to 48 ka and continued throughout the Middle Wisconsinan. Braided stream deposits were accumulating in the Athabasca River valley near Jasper townsite about 29 ka. In the Late Wisconsinan, Rocky Mountain and Cordilleran glaciers advanced through the area, initially damming lakes in a number of Front Range tributary valleys. During déglaciation, ice-marginal glaciofluvial activity and paragiacial debris flows dominated sedimentation. Glacial lakes were limited in extent. A radiocarbon date on shells from one small ice-marginal lake indicates that glaciers were well in retreat by about 12 ka. Alpine glaciers in the region were at or near their present limits by 10 ka.

Deposition Prediction of Debris Flow Alluvial Fan Based on Experimental Study

2012 ◽  
Vol 518-523 ◽  
pp. 4819-4822
Author(s):  
Jin Feng Liu ◽  
Shun Yang ◽  
Guo Qiang Ou
Keyword(s):  
Experimental Study ◽  
Debris Flow ◽  
Statistical Method ◽  
Laboratory Experiments ◽  
Empirical Models ◽  
Alluvial Fan ◽  
Disaster Prevention ◽  
Average Accuracy ◽  
Hazardous Area ◽  
Debris Flow Disaster

The deposition prediction of debris flow hazardous area is very important for organizing and implementing debris flow disaster prevention and reduction. This paper selected the data base from laboratory experiments and applied the multiple regression statistical method to establish a series of empirical calculation models for delimiting the debris flow hazardous areas on the alluvial fan. The empirical models for predicting the maximum deposition length (Lc), the maximum deposition width (Bmax) and the maximum deposition thichness (Z0) under the condition of different debris flow volumes (V), densities (rm) and slopes of accumulation area (θd) were establised. And the verification results indicated that the established models can predict the debris flow hazards area with the average accuracy of 86%.

scholarly journals Analysis of debris-flow recordings in an instrumented basin: confirmations and new findings

2012 ◽  
Vol 12 (3) ◽  
pp. 679-686 ◽  
Author(s):  
M. Arattano ◽  
L. Marchi ◽  
M. Cavalli
Keyword(s):  
Debris Flow ◽  
Alluvial Fan ◽  
Seismic Network ◽  
Low Flow ◽  
Main Peak ◽  
Flow Monitoring ◽  
Irregular Pattern ◽  
New Findings ◽  
Seismic Recording ◽  
Seismic Networks

Abstract. On 24 August 2006, a debris flow took place in the Moscardo Torrent, a basin of the Eastern Italian Alps instrumented for debris-flow monitoring. The debris flow was recorded by two seismic networks located in the lower part of the basin and on the alluvial fan, respectively. The event was also recorded by a pair of ultrasonic sensors installed on the fan, close to the lower seismic network. The comparison between the different recordings outlines particular features of the August 2006 debris flow, different from that of events recorded in previous years. A typical debris-flow wave was observed at the upper seismic network, with a main front abruptly appearing in the torrent, followed by a gradual decrease of flow height. On the contrary, on the alluvial fan the wave displayed an irregular pattern, with low flow depth and the main peak occurring in the central part of the surge both in the seismic recording and in the hydrographs. Recorded data and field evidences indicate that the surge observed on the alluvial fan was not a debris flow, and probably consisted in a water surge laden with fine to medium-sized sediment. The change in shape and characteristics of the wave can be ascribed to the attenuation of the surge caused by the torrent control works implemented in the lower basin during the last years.

scholarly journals Risk management on an alluvial fan: a case study of the 2008 debris-flow event at Villar Pellice (Piedmont, N-W Italy)

2010 ◽  
Vol 10 (5) ◽  
pp. 999-1008 ◽  
Author(s):  
M. Arattano ◽  
R. Conte ◽  
L. Franzi ◽  
D. Giordan ◽  
A. Lazzari ◽  
...  
Keyword(s):  
Debris Flow ◽  
Human Life ◽  
Alluvial Fan ◽  
Civil Protection ◽  
Emergency Situations ◽  
New Guidelines ◽  
Personal Accounts ◽  
Regional Authorities ◽  
North Western

Abstract. In the Piedmont Region (North-Western Italy), the regional authorities manage debris flow risk by following the ideal sequence of steps that are generally pursued in land planning and civil protection activities. Complex procedures and methods are elaborated and widely discussed with politicians, economists and the general public. On the contrary, in emergency situations, civil protection agencies generally prefer the adoption of simple and flexible criteria. In this paper, a catastrophic debris flow event, that occurred in 2008 in Villar Pellice, is described in this perspective, after an analysis of the triggering rainfalls and of the effects on human life and properties. The availability of a series of personal accounts coming from people who witnessed the occurrences before, during and after the event has allowed us to analyse, in detail, the dynamics of the event. Thanks to these accounts, it has been possible to propose new guidelines for the planning of the emergency activities in areas that are potentially prone to similar impulsive phenomena.

Late Quaternary paleodrainage reconstruction of the Maros River alluvial fan

Geomorphology ◽  
2014 ◽  
Vol 204 ◽  
pp. 49-60 ◽  
Author(s):  
Tímea Kiss ◽  
Borbála Sümeghy ◽  
György Sipos
Keyword(s):  
Late Quaternary ◽  
Alluvial Fan

scholarly journals Debris-flow activity in abandoned channels of the Manival torrent reconstructed with LiDAR and tree-ring data

2011 ◽  
Vol 11 (5) ◽  
pp. 1247-1257 ◽  
Author(s):  
J. Lopez Saez ◽  
C. Corona ◽  
M. Stoffel ◽  
A. Gotteland ◽  
F. Berger ◽  
...  
Keyword(s):  
Debris Flow ◽  
Tree Ring ◽  
Debris Flows ◽  
Temporal Distribution ◽  
Alluvial Fan ◽  
Tree Ring Data ◽  
Pine Trees ◽  
Spatio Temporal ◽  
Flow Activity ◽  
Abandoned Channels

Abstract. Hydrogeomorphic processes are a major threat in many parts of the Alps, where they periodically damage infrastructure, disrupt transportation corridors or even cause loss of life. Nonetheless, past torrential activity and the analysis of areas affected during particular events remain often imprecise. It was therefore the purpose of this study to reconstruct spatio-temporal patterns of past debris-flow activity in abandoned channels on the forested cone of the Manival torrent (Massif de la Chartreuse, French Prealps). A Light Detecting and Ranging (LiDAR) generated Digital Elevation Model (DEM) was used to identify five abandoned channels and related depositional forms (lobes, lateral levees) in the proximal alluvial fan of the torrent. A total of 156 Scots pine trees (Pinus sylvestris L.) with clear signs of debris flow events was analyzed and growth disturbances (GD) assessed, such as callus tissue, the onset of compression wood or abrupt growth suppression. In total, 375 GD were identified in the tree-ring samples, pointing to 13 debris-flow events for the period 1931–2008. While debris flows appear to be very common at Manival, they have only rarely propagated outside the main channel over the past 80 years. Furthermore, analysis of the spatial distribution of disturbed trees contributed to the identification of four patterns of debris-flow routing and led to the determination of three preferential breakout locations. Finally, the results of this study demonstrate that the temporal distribution of debris flows did not exhibit significant variations since the beginning of the 20th century.

scholarly journals Chronology of terraces in the Rio Grande rift, Socorro basin, New Mexico: Implications for terrace formation

Geosphere ◽  
2020 ◽  
Vol 16 (6) ◽  
pp. 1457-1478
Author(s):  
Brad D. Sion ◽  
Fred M. Phillips ◽  
Gary J. Axen ◽  
J. Bruce J. Harrison ◽  
David W. Love ◽  
...  
Keyword(s):  
New Mexico ◽  
Late Quaternary ◽  
Rio Grande ◽  
New Age ◽  
Alluvial Fan ◽  
Rio Grande Rift ◽  
Arid Environments ◽  
Alluvial Deposits ◽  
Continental Scale ◽  
Geomorphic Surfaces

Abstract The Rio Grande rift hosts a remarkable record of Quaternary river incision preserved in an alluvial terrace sequence that has been studied for more than a century. However, our understanding of Rio Grande incision history in central New Mexico since the end of basin filling ca. 0.78 Ma remains hampered by poor age control. Robust correlations among Rio Grande terrace sequences in central and southern New Mexico are lacking, making it difficult to address important process-related questions about terrace formation in continental-scale river systems. We present new age controls using a combination of 40Ar/39Ar, 36Cl surface-exposure, and 14C dating techniques from alluvial deposits in the central New Mexico Socorro area to document the late Quaternary incision history of the Rio Grande. These new age controls (1) provide constraints to establish a firm foundation for Socorro basin terrace stratigraphy, (2) allow terrace correlations within the rift basin, and (3) enable testing of alternative models of terrace formation. We identified and mapped a high geomorphic surface interpreted to represent the end of basin filling in the Socorro area and five distinct, post–Santa Fe Group (ca. 0.78 Ma) alloformations and associated geomorphic surfaces using photogrammetric methods, soil characterization, and stratigraphic descriptions. Terrace deposits exhibit tread heights up to 70 m above the valley floor and are 5 to >30 m thick. Their fills generally have pebble-to-cobble bases overlain by fine-to-pebbly sand and local thin silt and clay tops. Alluvial-fan terraces and associated geomorphic surfaces grade to former valley levels defined by axial terrace treads. Carbon-14 ages from detrital charcoal above and below a buried tributary terrace tread show that the most recent aggradation event persisted until ca. 3 ka during the transition from glacial to modern climate conditions. Drill-log data show widespread valley fill ∼30 m thick that began aggrading after glacial retreat in northern New Mexico and southern Colorado (ca. 14 ka). Aggradation during this transition was likely due to hillslope destabilization, increased sediment yield, decreased runoff, and reduced stream competence. Chlorine-36 ages imply similar controls on earlier terraces that have surface ages of ca. 27–29, 64–70, and 135 ka, and suggest net incision during glacial expansions when increased runoff favored down-cutting and bedload mobilization. Our terrace chronology supports existing climate-response models of arid environments and links tributary responses to the axial Rio Grande system throughout the central Rio Grande rift. The terrace chronology also reflects a transition from modest (60 m/m.y.) to rapid (300 m/m.y.) incision between 610 and 135 ka, similar to patterns observed throughout the Rio Grande rift and the western United States in general.

Late Quaternary sedimentation in Baffin Bay

1987 ◽  
Vol 24 (9) ◽  
pp. 1833-1846 ◽  
Author(s):  
A. E. Aksu ◽  
David J. W. Piper
Keyword(s):  
Debris Flow ◽  
Late Quaternary ◽  
Ocean Basin ◽  
The Arctic ◽  
Bottom Current ◽  
Eastern Canada ◽  
Baffin Bay ◽  
Quaternary Glaciation ◽  
Continental Slopes ◽  
Channel Systems

Baffin Bay is a small ocean basin that connects the Arctic and Atlantic oceans. The adjacent continental shelves have been extensively reworked during Quaternary glaciation. The shelf break generally lies between 200 and 500 m. The continental slope passes directly into the abyssal plain of Baffin Bay basin without any major submarine canyon – deep-sea fan system being present, except for a large smooth sediment apron in northern Baffin Bay.On the basis of over 50 piston cores, six Quaternary sediment facies are distinguished from detrital mineralogy (reflected in colour) and sediment texture. Facies A, B, and C are predominantly ice-rafted or are debris flow deposits, each with a distinct mineralogy. Facies D is turbidites and bottom-current sorted sands, silts, and muds. Facies E is hemipelagic sediment. Facies F consists of sediments ranging from slumps, through debris flow deposits, to fine-grained turbidites, with a distinctive provenance in northern Baffin Bay.These sediment facies appear to be partly controlled by glacial conditions. Hemipelagic facies E predominates during the present interglacial. During glacial stages, facies D turbidites were deposited. They resulted from slumping of proglacial sediments on the continental slopes off Greenland and Baffin Island. Facies C and F occurred on the continental slopes at these times. Ice-rafted facies A and B predominate at several horizons, reflecting a rapid breakup of ice shelves in northern Baffin Bay and increased rates of iceberg melting within the Bay. Overall sedimentation rates are relatively low, reflecting dry-base ice sheets in source areas.Deep-sea channel systems floored by sorted coarse sediments and bounded by muddy levees are absent in Baffin Bay, in contrast to mid-latitude glaciated continental margins off eastern Canada. These channel systems are the result of melting of wet-base glaciers, which provide a localized supply of sediment that is sorted by ice margin processes. In Baffin Bay, most glacial sediments are derived by calving of icebergs, probably from dry-base glaciers. Sediments are gradually released over large areas as the bergs melt, and are subsequently redistributed by debris flows.

scholarly journals The linkage between hillslope vegetation changes and late-Quaternary fluvial-system aggradation in the Mojave Desert revisited

2014 ◽  
Vol 2 (1) ◽  
pp. 181-213
Author(s):  
J. D. Pelletier
Keyword(s):  
Vegetation Cover ◽  
Mojave Desert ◽  
Process Model ◽  
Late Quaternary ◽  
Drainage Density ◽  
Alluvial Fan ◽  
System Response ◽  
Vegetation Changes ◽  
Fluvial System ◽  
Extreme Storm

Abstract. Valley-floor-channel and alluvial-fan deposits and terraces in the southwestern US record multiple episodes of late Quaternary fluvial aggradation and incision. Perhaps the most well constrained of these episodes took place from the latest Pleistocene to the present in the Mojave Desert. One hypothesis for this episode, i.e. the paleo-vegetation change hypothesis (PVCH), posits that a reduction in hillslope vegetation cover associated with the transition from Pleistocene woodlands to Holocene desert scrub generated a pulse of sediment that triggered a primary phase of aggradation downstream, followed by channel incision, terrace abandonment, and initiation of a secondary phase of aggradation further downstream. A second hypothesis, i.e. the extreme-storm hypothesis, attributes episodes of aggradation and incision to changes in the frequency and/or intensity of extreme storms. In the past decade a growing number of studies has advocated the extreme-storm hypothesis and challenged the PVCH on the basis of inconsistencies in both timing and process. Here I show that in eight out of nine sites where the timing of fluvial-system aggradation in the Mojave Desert is reasonably well constrained, measured ages of primary aggradation and/or incision are consistent with the predictions of the PVCH if the time-transgressive nature of paleo-vegetation changes with elevation is fully taken into account. I also present an alternative process model for PVCH that is more consistent with available data and produces sediment pulses primarily via an increase in drainage density (i.e. a transformation of hillslopes into low-order channels) rather than solely via an increase in sediment yield from hillslopes. This paper further documents the likely important role of changes in upland vegetation cover and drainage density in driving fluvial-system response during semiarid-to-arid climatic changes.

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