scholarly journals Landslide hypothesis for the origin of Haleakala volcano's crater and great valleys, Hawaii

Geosphere ◽  
2021 ◽  
Vol 17 (5) ◽  
pp. 1405-1421
Author(s):  
Kim M. Bishop
Keyword(s):  
Slope Failure ◽  
Rift Zone ◽  
Hawaiian Island ◽  
Summit Crater ◽  
Annual Rainfall ◽  
Fluvial Erosion ◽  
Lateral Margins ◽  
Northeastern Flank ◽  
Valley Incision ◽  
Giant Landslide

Abstract Active Haleakala volcano on the island of Maui is the second largest volcano in the Hawaiian Island chain. Prominently incised in Haleakala's slopes are four large (great) valleys. Haleakala Crater, a prominent summit depression, formed by coalescence of two of the great valleys. The great valleys and summit crater have long been attributed solely to fluvial erosion, but two significant enigmas exist in the theory. First, the great valleys of upper Keanae/Koolau Gap, Haleakala Crater, and Kaupo Gap are located in areas of relatively low annual rainfall. Second, the axes of some valley segments are oblique for long distances across the volcanic slopes. This study tested the prevailing erosional theory by reconstructing the volcano's topography just prior to valley incision. The reconstruction produces a belt along the volcano's east rift zone with a morphology that is inconsistent with volcanic aggradation alone, but it is readily explained if it is assumed the surface was displaced along scarps formed by a giant landslide on Haleakala's northeastern flank. Although the landslide head location is well defined, topographic evidence is lacking for the toe and lateral margins. Consequently, the slope failure is interpreted as a sackung-style landslide with a zone of deep-seated distributed shear and broad surface warping downslope of the failure head. Maximum downslope displacement was likely in the range of 400–800 m. Capture of runoff at the headscarps formed atypically large streams that carved Haleakala's great valleys and explains their existence in low-rainfall areas and their slope-oblique orientations. Sackung-style landslides may be more prevalent on Hawaiian volcanoes than previously recognized.

scholarly journals Erosion Failure of a Soil Slope by Heavy Rain: Laboratory Investigation and Modified GA Model of Soil Slope Failure

2019 ◽  
Vol 16 (6) ◽  
pp. 1075 ◽  
Author(s):  
Xiaofei Jing ◽  
Yulong Chen ◽  
Changshu Pan ◽  
Tianwei Yin ◽  
Wensong Wang ◽  
...  
Keyword(s):  
Laboratory Investigation ◽  
Slope Failure ◽  
Slope Angle ◽  
Heavy Rain ◽  
Annual Rainfall ◽  
Soil Slope ◽  
Saturated Zone ◽  
Wetting Front ◽  
Rainfall Condition ◽  
The Impact

Rainfall has been identified as one of the main causes for slope failures in areas where high annual rainfall is experienced. The slope angle is important for its stability during rainfall. This paper aimed to determine the impact of the angle of soil slope on the migration of wetting front in rainfall. The results proved that under the same rainfall condition, more runoff was generated with the increase of slope angle, which resulted in more serious erosion of the soil and the ascent of wetting front. A modified Green-Ampt (GA) model of wetting front was also proposed considering the seepage in the saturated zone and the slope angle. These findings will provide insights into the rainfall-induced failure of soil slopes in terms of angle.

scholarly journals Categorization of Slope Failure in Southern Malaysia using Total Estimated Hazard (TEHD) Method

2020 ◽  
Vol 9 (1) ◽  
pp. 1966-1971
Keyword(s):  
Slope Failure ◽  
Secondary Data ◽  
Landslide Hazard ◽  
Public Works ◽  
Annual Rainfall ◽  
Hazard Evaluation ◽  
Geologic Hazard ◽  
Data Resource ◽  
High Hazard ◽  
Very High

Slope is a measure of steepness or the degree of inclination of a feature relative to the horizontal plane. One of the phenomenon or incidents of a slope was called as slope failure or landslide. Slope failure was a major natural disaster that had affected the country in terms of injuries, deaths, property damage, destruction of services, public inconvenience and economic as well as financial losses. Slope failure cases were very serious geologic hazard disaster that happened in many countries around the world. The aim of this paper is to determine the category of slope failure in the state of Johor based on Landslide Hazard Zonation (LHZ). Data were calculated by using Total Estimated Hazard (TEHD) value method which considered six factors effecting the slope failure, including lithology; slope steepness, topography, land use class, annual rainfall and type of soil. Data on the factors were collected from Malaysia Public Works Department (JKR) inspection form, website, and secondary data resource. After that weight for each factor were identified by referring to Landslide Hazard Evaluation Factor (LHEF) rating scheme. Then determination of LHZ was done according to TEHD values which have five hazard zones; (1) very low; (2) low; (3) medium; (4) high; and (5) very high. The results of this study found that out of total fifty two cases there were three medium hazard (MH), twenty seven high hazard (HH) and twenty two very high hazard (VHH). Comparison between actual data from JKR and total 52 locations of slope failure in Johor showed that 94% accuracy, TEHD equation could calculate potential slope failure hazards in Johor very well.

The rise of high mountain peaks: Feedbacks between orographic precipitation, fluvial erosion and flexural isostasy

2020 ◽  
Author(s):  
Jörg Robl ◽  
Stefan Hergarten
Keyword(s):  
Windward Side ◽  
Leeward Side ◽  
Orographic Precipitation ◽  
High Mountain ◽  
Precipitation Pattern ◽  
Fluvial Erosion ◽  
Erosion Rates ◽  
Erosional Unloading ◽  
Orogenic Plateaus ◽  
Valley Incision

<p>The majority of the highest mountain peaks on Earth is located at the dissected rim of large orogenic plateaus such as the Tibetan Plateau or the Altiplano. The striking spatial coexistence of deep, incised valleys and extraordinary high peaks located at the interfluves led to the idea of a common formation even a hundred years ago: focused erosion in valleys triggers the rise of mountain peaks due to erosional unloading and isostatically driven uplift. Ridgelines rise at the interfluves parallel to major rivers, but an additional ridgeline forms perpendicular to the principal flow direction separating the dissected rim from the undissected center of the plateau. As major rivers originate within the plateau and bypass the highest peaks, the latter rigdeline does not form a principal drainage divide. However, it forms a strong orographic barrier with wet conditions at the windward and dry conditions towards the plateau center at the leeward side. The height of the ridgeline is controlled by valley incision via erosional unloading and isostatic uplift.  If the precipitation pattern responsible for localized valley incision is controlled by the geometry of orographic barriers, a series of complex feedbacks between precipitation, erosion and ridgeline uplift (including the evolution of the highest peaks) occurs.</p><p>In this study, we present first results of a novel numerical model, which couples (a) fluvial erosion based on the stream power law, (b) flexural isostasy including viscous relaxation and (c) orographic precipitation based on the advection and diffusion of moisture and its reaction on topographic barriers. Originating from a simple model setup with a plateau in the center of the model domain and moisture transported along a predominant wind direction, we explore the co-formation of valleys and the rise of ridgelines including the growth of extraordinary high peaks. As the evolving topography controls the precipitation pattern, erosion rates are high at the wet windward side of the ridgeline, which parallels the plateau rim, while the leeward side towards the plateau center is characterized by low precipitation and very low erosion rates. As it prevents elevated low-relief areas from dissection, we suggest that this mechanism is a principal cause for the longevity of orogenic plateaus.</p>

scholarly journals Influence of extreme long-term rainfall and unsaturated soil properties on triggering of a landslide – a case study

2017 ◽  
Author(s):  
Håkon Heyerdahl
Keyword(s):  
Shear Strength ◽  
Slope Stability ◽  
Soil Properties ◽  
Unsaturated Soil ◽  
Slope Failure ◽  
Annual Rainfall ◽  
Soil Suction ◽  
Year 2000

Abstract. A case study of a natural slope in Eastern Norway that failed after extreme long-term rainfall in year 2000 was performed. Effect of soil suction on soil shear strength was investigated for intact specimens of Quaternary silt/sand, using an unsaturated shear box apparatus. Common prediction models under-predicted the unsaturated shear strength, particularly for small suctions. Analyses of rainfall infiltration were performed for silt and sand slopes, based on retention curves measured in laboratory. For normal annual rainfall of 800 mm/year the model slope is theoretically stable. Extreme rainfall (240 mm in 30 days) during the autumn of year 2000 results in a rise of groundwater and loss of soil suction in the vadose zone. To reach theoretical slope failure, lower cohesion had to be assumed than measured in laboratory. High cohesion may be caused by cementation in shallow soil layers, and lower cohesion may be appropriate. Slope stability analyses based on transient seepage analysis of rainfall show gradual decrease of slope stability towards slope failure (for the silt slope). With expected future increase in rainfall, more attention is needed on the role of unsaturated soil properties in rainfall triggering of landslides in different soil types, climatic conditions and geologic settings.

scholarly journals SPATIAL MODELING VARIOUS TYPES OF SLOPE FAILURE USING ARTIFICIAL NEURAL NETWORK (ANN) IN PULAU PINANG, MALAYSIA/PEMODELAN RUANGAN PELBAGAI JENIS KEGAGALAN CERUN MENGGUNAKAN RANGKAIAN SARAF BUATAN (ANN) DI PULAU PINANG, MALAYSIA

2018 ◽  
Vol 80 (4) ◽  
Author(s):  
Nuriah Abd Majid ◽  
Ruslan Rainis ◽  
Wan Mohd Muhiyuddin Wan Ibrahim
Keyword(s):  
Neural Network ◽  
Artificial Neural Network ◽  
Vegetation Index ◽  
Slope Failure ◽  
Field Trips ◽  
Annual Rainfall ◽  
Slope Aspect ◽  
Data Set ◽  
Artificial Neural ◽  
Artificial Neural Network Ann

This paper discusses the modeling of various types of slope failure using the artificial neural network (ANN) in Penang. Slope failure areas identified by field trips. However, the existing models do not categorize the various types of slope failure, therefore the model to be developed will categorize a variety of types of slope failure has occurred The objective of the study is to model various types of slope failure using an artificial neural network (ANN). A total of 12 variables that influence the occurrence of slope failure is used to develop spatial model of slope failure. Among the factors are distant from slope failure to road, distant from slope failure to river, distant from slope failure to lineament, lithology, land use, soil series, average annual rainfall, slope aspect, slope steepness, topographic elevation (DEM), the curvature of the slope and vegetation index. The results of this study show a satisfactory performance in which the accuracy of the original model is 76.63%. The performance of the model is evaluated using independent data set of 20%, and the accuracy of 73.85%.

Ethnocultural Differences in PTSD and Anger in Hawaiian Island Veterans

2010 ◽  
Author(s):  
Heather M. Sones ◽  
Steven Thorp ◽  
Carolyn J. Greene ◽  
Kathleen M. Grubbs ◽  
Leslie A. Morland
Keyword(s):  
Hawaiian Island

THE ROLE OF GRASSLAND IN MANAGEMENT

1968 ◽  
pp. 44-49
Author(s):  
B.K. Cameron
Keyword(s):  
Soil Temperature ◽  
Annual Rainfall ◽  
Silt Loam ◽  
Average Annual Rainfall ◽  
Very High ◽  
Wilting Point

THE PROPERTY to be discussed is a mixed sheep and cropping unit, situated ei ht a miles east of Ashburton and midway between the Ra aia and the Ashburton rivers. Average annual rainfall is 27 in., evenly spread, but there is very high summer evaporation and therefore frequent droughts. On average, the soil is below wilting point for 40 to 50 days each summer. Winters are cold with the soil temperature being below 48°F for about four months each year. The soil is a Lismore stony silt loam averaging 9 in. in depth over gravel.

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