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101.
A semi-empirical approach using fore- or after-shockrecords as Green's functions is applicable to thesimulation of strong ground motion, however suchrecords are obviously not available for predictionpurposes. Thus we have predicted ground motion fora hypothetical large earthquake from other minorevents by adopting a distance correction based ongeometrical spreading. Another difficulty inprediction is fault modeling. Surface traces weresimplified as fault models 27, 46, 55, and 77 km inlength. Further, the actual fault rupture may beinhomogeneous, so an asperity distribution isassumed. This asperity model assumes thatdislocation and stress drop are double than theaverage values. Although, the near field term isneglected in our simulation, no significantdifference was seen in the motions estimated byindividual models for periods up to 2.0 seconds. This indicates that the dependence of source size issmall for strong motion, perhaps as a result of therandom summation of high-frequency phases.  相似文献   
102.
Estimating ground motions using recorded accelerograms   总被引:1,自引:0,他引:1  
A procedure for estimating ground motions using recorded accelerograms is described. The premise of the study is the assumption that future ground motions will be similar to those observed for similar site and tectonic situations in the past. Direct techniques for scaling existing accelerograms have been developed, based on relative estimates of local magnitude,M L . Design events are described deterministically in terms of fault dimension, tectonic setting (stress drop), fault distance, and site conditions. A combination of empirical and theoretical arguments is used to develop relationships betweenM L and other earthquake magnitude scales. In order to minimize scaling errors due to lack of understanding of the physics of strong ground motion, the procedure employs as few intermediate scaling laws as possible. The procedure conserves a meaningful measure of the uncertainty inherent when predicting ground motions from simple parameterizations of earthquake sources and site conditions.  相似文献   
103.
104.
Smaller equipment has been developed for sampling and measuring H2 in fault zones. A considerable volume of hydrogen emission, suggesting the presence of fluid paths along fault zones, was detected within a 1‐h simple field procedure at an active fault in Central Japan, the Atotsugawa Fault. The equipment enabled measurements in a thin fault gouge with a thickness of 10 mm; this led to pervasive sampling from small fault zones hosted in harder rocks. A rapid evaluation of the spatio‐temporal heterogeneity of hydrogen emissions along the faults, using the present method, would increase knowledge of fluid circulation around faults.  相似文献   
105.
Since the 1970s, the crested porcupine Hystrix cristata has shown a marked range expansion in Italy. A web page has been created to collect occurrences of this species to monitor its distribution redefinition. Thus, aims of this work were (i) to identify the main predictors promoting the distribution of this large rodent in Italy and (ii) to predict its potential expansion under future climate change scenarios. A total of 1674 locations were used for this analysis, i.e., all those collected through the web page, with the exception of recently introduced populations (Sardinia, Western Liguria and Province of Varese). The current distribution of the crested porcupine covers a total of 135,177 km2, as estimated through ensemble predictions. Future climate change scenarios for 2050 and 2070 show that a further range expansion by this species would occur up to 225,576 km2, mainly towards areas where the species was historically absent. The increase of isothermality (i.e., the ratio between the mean diurnal and the annual temperature range) and the mean temperature of the driest months would help crested porcupines to reach high altitudes, e.g., in the Alps. In mountain habitats, the ongoing global warming is shifting the distribution of European forests to high elevations, thus potentially providing porcupines with suitable habitats. A reduction in snow cover and the snow period at ground level would remove an important barrier to the range expansion of the crested porcupine in Italy, and thus facilitate digging and food search by this large rodent. Despite being protected at national and international levels, the crested porcupine is reported to be an introduced species to Italy and, therefore, monitoring its range expansion is required. Furthermore, there are complaints about crop damage in agriculture ecosystems, and the species is still widely poached, thus additional management practices are required. Thus, given the conservation interest of this large rodent, an integrated and constantly updated monitoring system that sustains an addressed set of decision-making tools is recommended.  相似文献   
106.
This paper estimates property loss and business interruption loss under scenarios of storm surge inundation to explore the economic impact of climate change on Ise Bay, Japan. Scenarios-based analyses are conducted with respect to Typhoon Vera, which caused the most severe storm surge in the recorded history of Japan in 1959. Four different hazard scenarios are chosen from a series of typhoon storm surge inundation simulations: Typhoon Vera’s landfall with respect to the condition of the past seawall; Typhoon Vera’s landfall with respect to the condition of the current seawall; intensifying Typhoon Vera, but retaining its original tracks; and intensifying Typhoon Vera, but choosing the worst tracks from various possible typhoon tracks. Our economic loss estimation takes advantage of fine geographical scale census and economic census data that enable us to understand the spatial distribution of property loss and business interruption loss as well as identify the most potentially affected areas and business sectors on a sub-city scale. By comparing the property loss and business interruption loss caused by different hazard scenarios, the effect of different seawalls is evaluated and the economic impact of future climate change is estimated. The results indicate that although the current seawall can considerably reduce the scale of losses, climate change can cause Ise Bay to experience more serious storm surge inundation. Moreover, the resulting economic losses would increase significantly owing to a combination of climate change and the worst track scenario. It is, therefore, necessary to consider more countermeasures to adapt to climate change in this area.  相似文献   
107.
Rabaul tide gauge records from 1968 through 1985 give the amount of vertical movement in the northern part of Rabaul Caldera. Monthly mean sea level data were compared with other regional tide gauge stations to remove large scale oceanographic effects. No large vertical movements (> 0.3 cm/yr) were noted in this portion of the caldera. The results of sea level measurements at other points around the caldera, from 1981 through 1983 are consistent with the 1 to 10 cm of uplift observed on Matupit Island from optical leveling surveys. There was relatively little vertical movement (~ 0.1 cm/yr) in the Vulcan area.  相似文献   
108.
Rabaul tide gauge records from 1968 through 1985 give the amount of vertical movement in the northern part of Rabaul Caldera. Monthly mean sea level data were compared with other regional tide gauge stations to remove large scale oceanographic effects. No large vertical movements (> 0.3 cm/yr) were noted in this portion of the caldera. The results of sea level measurements at other points around the caldera, from 1981 through 1983 are consistent with the 1 to 10 cm of uplift observed on Matupit Island from optical leveling surveys. There was relatively little vertical movement ( 0.1 cm/yr) in the Vulcan area.  相似文献   
109.
In-water algorithms for OCTS standard products were developed using in situ data and installed for operationally processing at NASDA/EOC. This paper describes the in-water algorithms Version 1.0 for chlorophylla concentration, pigment concentration, and attenuation coefficient at a wavelength of 490 nm. The selected OCTS standard algorithms (Ver. 1.0) are as follows:   相似文献   
110.
The reaction kinetics of metamorphic minerals can be subdivided into interface‐ and diffusion‐controlled kinetics. The discrimination of reaction kinetics is crucial for estimating reaction rates. Here, we propose a new and simple method for discriminating reaction kinetics. This method requires measuring only the initial and final grain sizes during growth. The reaction kinetics is inferred from different plotted arrays of initial vs. final grain sizes after the mineral growth. Using metamorphic zircon, we take detrital core sizes as the initial sizes and post‐metamorphic grain sizes as the final sizes. The application of the method to the subduction‐related high‐pressure Nagasaki metamorphic complex in Japan shows that this metamorphic zircon grew under interface‐controlled kinetics even at the relatively low temperature of 440°C. This method is potentially applicable to other minerals that have time‐markers, such as chemical zoning or internal structures that are captured at a given point in time during growth.  相似文献   
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