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1.
The solution of two-dimensional problem of an interface breaking long inclined dip-slip fault in two welded half-spaces is
well known. The purpose of this note is to obtain the corresponding solution for a blind fault. The solution is valid for
arbitrary values of the fault-depth and the dip angle. Graphs showing the variation of the displacement field with the distance
from the fault, for different values of fault depth and dip angle are presented. Contour maps showing the stress field around
a long dip-slip fault are also obtained 相似文献
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Simulation of the Arabian Sea Tsunami propagation generated due to 1945 Makran Earthquake and its effect on western parts of Gujarat (India) 总被引:1,自引:1,他引:0
The 1945 Tsunami generated due to Makran Earthquake in the Arabian Sea was the most devastating tsunami in the history of
the Arabian Sea and caused severe damage to property and loss of life. It occurred on 28th November 1945, 21:56 UTC (03:26
IST) with a magnitude of 8.0 (M
w), originating off the Makran Coast of Pakistan in the Arabian Sea. It has impacted as far as Mumbai in India and was noticed
up to Karvar Coast, Karnataka. More than 4,000 people were killed as a result of the earthquake and the tsunami. In this paper
an attempt is made for a numerical simulation of the tsunami generation from the source, its propagation into the Arabian
Sea and its effect on the western coast of India through the use of a numerical model, referred to as Tunami-N2. The present
simulation is carried out for a duration of 300 min. It is observed from the results that the simulated arrival time of tsunami
waves at the western coast of India is in good agreement with the available data sources. The paper also presents run-up elevation
maps prepared using Shuttle Radar Topographic Mission (SRTM) data, showing the possible area of inundation due to various
wave heights along different parts of the Gujarat Coast. Thus, these results will be useful in planning the protection measures
against inundation due to tsunami and in the implementation of a warning system. 相似文献
5.
We present the seismic energy, strain energy, frequency–magnitude relation (b-value) and decay rate of aftershocks (p-value) for the aftershock sequences of the Andaman–Sumatra earthquakes of December 26, 2004 (M
w 9.3) and March 28, 2005 (M
w 8.7). The energy released in aftershocks of 2004 and 2005 earthquake was 0.135 and 0.365% of the energy of the respective
mainshocks, while the strain release in aftershocks was 39 and 71% for the two earthquakes, respectively. The b-value and p-value indicate normal value of about 1. All these parameters are in normal range and indicate normal stress patterns and
mechanical properties of the medium. Only the strain release in aftershocks was considerable. The fourth largest earthquake
in this region since 2004 occurred in September 2007 off the southern coast of Island of Sumatra, generating a relatively
minor tsunami as indicated by sea level gauges. The maximum wave amplitude as registered by the Padang, tide gauge, north
of the earthquake epicenter was about 60 cm. TUNAMI-N2 model was used to investigate ability of the model to capture the minor
tsunami and its effect on the eastern Indian Coast. A close comparison of the observed and simulated tsunami generation, propagation
and wave height at tide gauge locations showed that the model was able to capture the minor tsunami phases. The directivity
map shows that the maximum tsunami energy was in the southwest direction from the strike of the fault. Since the path of the
tsunami for Indian coastlines is oblique, there were no impacts along the Indian coastlines except near the coast of epicentral
region. 相似文献
6.
Quantitative assessment of landslide hazard along transportation lines using historical records 总被引:2,自引:1,他引:1
In this paper, a quantitative landslide hazard model is presented for transportation lines, with an example for a road and
railroad alignment, in parts of Nilgiri hills in southern India. The data required for the hazard assessment were obtained
from historical records available for a 21-year period from 1987 to 2007. A total of 901 landslides from cut slopes along
the railroad and road alignment were included in the inventory. The landslides were grouped into three magnitude classes based
on the landslide type, volume, scar depth, and run-out distance. To calculate landslide hazard, we estimated the total number
of individual landslides per kilometer of the (rail) road for different return periods, based on the relationship between
past landslides (recorded in our database) and triggering events. These were multiplied by the probability that the landslides
belong to a given magnitude class. This gives the hazard for a given return period expressed as the number of landslides of
a given magnitude class per kilometer of (rail) road. The relationship between the total number of landslides and the return
period was established using a Gumbel distribution model, and the probability of landslide magnitude was obtained from frequency–volume
statistics. The results of the analysis indicate that the total number of landslides, from 1- to 50-year return period, varies
from 56 to 197 along the railroad and from 14 to 82 along the road. In total, 18 hazard scenarios were generated using the
three magnitude classes and six return periods (1, 3, 5, 15, 25, and 50 years). The hazard scenarios derived from the model
form the basis for future direct and indirect landslide risk analysis along the transportation lines. The model was validated
with landslides that occurred in the year 2009. 相似文献
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The objective of analyzing hazard and risk in an area is to utilize the result in selecting appropriate landslide risk reduction strategies. However, this does not happen always, and most often results of the hazard and risk analysis remain at an academic level. The under or non-utilization of results in pre-disaster planning could be due to several reasons, including difficulties in understanding the scientific content/meaning of the models, and lack of information on the practical significance and utility of the models. In this study, an attempt is made to highlight the uses of hazard and risk information in different landslide risk reduction strategies along a transportation corridor in Nilgiri, India. At first, a quantitative analysis of landslide hazard and risk was made. The obtained information was then incorporated in risk reduction options such as land use zoning, engineering solutions, and emergency preparedness. For emergency preparedness, the perception of the local Nilgiri communities toward landslide risk was evaluated and simplified maps were generated for the benefit and understanding of end users. A rainfall threshold-based early warning system was presented, which could be used in risk awareness programs involving public participation. The use of quantitative risk information in the cost-benefit analysis for the planning of structural measures to protect the road and railway alignments was also highlighted, and examples were shown how the transport organizations could implement these measures. Finally, the study provided examples of the utility of hazard and risk information for spatial planning and zoning, indicating areas where the landslide hazard is too high for planning future developments. 相似文献
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GeoJournal - Urban expansion of the Indian metropolitan cities has reached the rural peripheries. There have been social, economic, and environmental consequences of this process of... 相似文献
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10.
Present paper aims to study the phenomenon of reflection and transmission when an inhomogeneous wave strikes some discontinuity in a composite porous medium saturated by two immiscible viscous fluids. The incident wave splits into six reflected and six transmitted waves at the interface. All reflected and transmitted waves are inhomogeneous in nature with different directions of propagation vector and attenuation vector. A dimensionless parameter \(\varsigma \in [0, 1]\) is introduced to represent the extent of connection among the pores at the interface. Expression of Umov–Poynting vector is derived to obtain energy flux vector. Continuity of energy flux vector at the interface gives the required boundary conditions for the system. Connecting parameter \(\varsigma \) is also employed in boundary conditions to model the partial connection of pores at the interstices of two media. For numerical discussion we consider a porous medium composed of sandstone and ice, saturated with oil and water. The effect of parameter \(\varsigma \) and angle of incidence is determined numerically on the amplitude and the energy ratios of reflected and transmitted waves. 相似文献