Rapid and accurate identification of potential structural deficiencies is a crucial task in evaluating seismic vulnerability of large building inventories in a region. In the case of multi-story structures, abrupt vertical variations of story stiffness are known to significantly increase the likelihood of collapse during moderate or severe earthquakes. Identifying and retrofitting buildings with such irregularities—generally termed as soft-story buildings—is, therefore, vital in earthquake preparedness and loss mitigation efforts. Soft-story building identification through conventional means is a labor-intensive and time-consuming process. In this study, an automated procedure was devised based on deep learning techniques for identifying soft-story buildings from street-view images at a regional scale. A database containing a large number of building images and a semi-automated image labeling approach that effectively annotates new database entries was developed for developing the deep learning model. Extensive computational experiments were carried out to examine the effectiveness of the proposed procedure, and to gain insights into automated soft-story building identification.
On the basis of data obtained by the Halogen Occultation Experiment (HALOE) on the Upper Atmosphere Research Satellite (UARS) box model calculations are performed to investigate the ozone budget in the upper stratosphere. The HALOE data comprise measurements of major source gases and key chemical species involved in the ozone destruction cycles. In comparison to earlier calculations using version 17 of the HALOE data, the calculated ozone destruction rate increases when the updated data version 18 is used. However, as with the previous study using version 17 of the HALOE data, no evidence for a significant model ozone deficit is found. 相似文献
Basaltic lavas from the Three Sisters and Dalles Lakes were erupted from two isolated vents in the central Washington Cascades
at 370–400 ka and 2.2 Ma, respectively, and have distinct trace element compositions that exemplify an important and poorly
understood feature of arc basalts. The Three Sisters lavas are calc-alkaline basalts (CAB) with trace element compositions
typical of most arc magmas: high ratios of large-ion-lithophile to high-field-strength elements (LILE/HFSE), and strong negative
Nb and Ta anomalies. In contrast, the Dalles Lakes lavas have relatively low LILE/HFSE and no Nb or Ta anomalies, similar
to ocean-island basalts (OIB). Nearly all Washington Cascade basalts with high to moderate incompatible element concentrations
show this CAB or OIB-like compositional distinction, and there is pronounced divergence between the two magma types with a
large compositional gap between them. We show that this trace element distinction can be easily explained by a simple model
of flux-melting of the mantle wedge by a fluid-rich subduction component (SC), in which the degree of melting (F) of the peridotite
source is correlated with the amount of SC added to it. Distinctive CAB and OIB-like trace element compositions are best explained
by a flux-melting model in which dF/dSC decreases with increasing F, consistent with isenthalpic (heat-balanced) melting.
In the context of this model, CAB trace element signatures simply reflect large degrees of melting of strongly SC-fluxed peridotite
along relatively low dF/dSC melting trends, consistent with derivation from relatively cold mantle. Under other conditions
(i.e., small degrees of melting or large degrees of melting of weakly SC-fluxed peridotite [high dF/dSC]), either OIB- or
MORB (mid-ocean ridge basalt)-like compositions are produced. Trace element and isotopic compositions of Washington Cascade
basalts are easily modeled by a correlation between SC and F across a range of mantle temperatures. This implies that the
dominant cause of arc magmatism in this region is flux melting of the mantle wedge.
Received: 2 March 1999 / Accepted: 18 August 1999 相似文献
Climate change poses a significant challenge for the future of Northern Ireland’s coast due to impacts that include, inter alia, mean sea level rise of between 13 cm and 74 cm by 2050. Whilst flooding is regarded as a major hazard in the United Kingdom (UK), to date Northern Ireland’s experiences of coastal flooding have been infrequent and less severe compared to those in England and Wales. Similarly, coastal erosion has historically been, and remains, only a minor concern in Northern Ireland. Partly as a result of this, Government administrative arrangements for Flood and Coastal Erosion Risk Management (FCERM) in Northern Ireland operate in the absence of any statutory provision for coastal erosion, as well as without formal or strategic shoreline management planning and any integrated flood and coastal erosion risk management policy. This paper provides a commentary on Northern Ireland’s approach to FCERM, comparing this with its UK counterparts, highlighting both congruence and divergence in policy evolution and development. It is noted that the recent EU Floods Directive has been a significant catalyst and that the current institutional landscape for FCERM is in flux. 相似文献
The participative, 'bottom-up' approaches of contemporary European ICZM (integrated coastal zone management) are ineffectual and unsustainable. The approach lacks the authority and resources to deliver ICZM and should be abandoned. A new model of ICZM in a predominantly sectoral administrative framework is presented. It requires that capacity be built in existing statutory authorities and in-house ICZM groups be established. Time-limited participatory projects would be used to gain information on conflicts and issues that transcend existing sectoral boundaries, but this information would be passed to the established statutory authorities for action. A sound statutory and legislative basis is the essential prerequisite for effective coastal management – not voluntary partnerships. 相似文献
Landslides are a widespread, frequent, and costly hazard in Seattle and the Puget Sound area of Washington State, USA. Shallow
earth slides triggered by heavy rainfall are the most common type of landslide in the area; many transform into debris flows
and cause significant property damage or disrupt transportation. Large rotational and translational slides, though less common,
also cause serious property damage. The hundreds of landslides that occurred during the winters of 1995–96 and 1996–97 stimulated
renewed interest by Puget Sound communities in identifying landslide-prone areas and taking actions to reduce future landslide
losses. Informal partnerships between the U.S. Geological Survey (USGS), the City of Seattle, and private consultants are
focusing on the problem of identifying and mapping areas of landslide hazard as well as characterizing temporal aspects of
the hazard. We have developed GIS-based methods to map the probability of landslide occurrence as well as empirical rainfall
thresholds and physically based methods to forecast times of landslide occurrence. Our methods for mapping landslide hazard
zones began with field studies and physically based models to assess relative slope stability, including the effects of material
properties, seasonal groundwater levels, and rainfall infiltration. We have analyzed the correlation between historic landslide
occurrence and relative slope stability to map the degree of landslide hazard. The City of Seattle is using results of the
USGS studies in storm preparedness planning for emergency access and response, planning for development or redevelopment of
hillsides, and municipal facility planning and prioritization. Methods we have developed could be applied elsewhere to suit
local needs and available data. 相似文献
The line absorption probability distribution functions and the reemission coefficients are derived for the non-coherent scattering functionsRIII andRIV. The appropriate line profile function forRIII is shown to be a simple Voigt function, while forRIV, the line absorption probability distribution function is more complex involving a linear combination of two Voigt functions and another more complex probability distribution. The structure of the reemission coefficients forRIII andRIV is then discussed. 相似文献
Black Butte is an early Miocene basaltic volcanic neck that forms a prominent landmark as the highest peak of the Gravelly Range, southwestern Montana. The intrusion cuts mid-Cenozoic and older sedimentary rocks near the eastern margin of the Overthrust Belt.
After erosional removal of the Late Cretaceous Frontier Formation, quartzite-rich detritus from ultimate sources probably far to the west was deposited in the area and now forms a diamicton that rests on striated bedrock. This unit, previously interpreted as a till and as a mudflow deposit, probably represents Upper Cretaceous or lower Tertiary, syntectonic alluvial-fan sediments. These were deposited after the Gravelly Arch had begun to rise and were deformed during overthrusting from the west or possibly during mass movement as the basal part of a landslide.
Scattered cobbles of hard quartzite in the diamicton are crushed. If this crushing occurred within aggregates of coarse clasts that were momentarity in point contact with one another, it does notrequire either overthrusting or mass movement of extremely thick depositional overburden. But if a major thrust sheet did move over the diamicton, the leading edge of the Overthrust Belt must extend considerably further east of where it is currently recognized in this area.
Volcanic and volcaniclastic rocks were deposited in the area throughout much or all of Oligocene time. These include tuffaceous mudstone as much as 265 m thick that contains vertebrate fossils of Chadronian through Whitneyan age. The KAr age of biotite in an airfall tuff within this section at nearby Lion Mountain is 31.4 Ma, and the KAr age of an alkaline basaltic flow at the top of the Lion Mountain section is 30.8 Ma. These tuffaceous rocks and basalt on Lion Mountain correlate with volcaniclastics in Wyoming and as far east as Nebraska and the Dakotas.
Eruptions at Black Butte, dated previously at 22.9 Ma, begun with phreatomagmatic explosions that deposited tuff across an irregular topographic surface cut in the section of tuffaceous mudstone into which the Black Butte plug was emplaced. The alkali basalt magma differentiated to yield the relatively rare rock typetephritic phonolite during fractional crystallization and segregation in situ of potassic late liquids.
Lava flows from Black Butte and the nearby Lion Mountain volcanic center may have covered much of this part of the Gravelly Range but have been mostly removed owing to erodability of the thick blanket of mudstone on which they rested.
Removal of mudstone that contained the Black Butte intrusion involved massive slumping. Mass movement of the diamicton beneath the mudstone is occurring today as an earthflow down the west-dipping structural and topographic slope of the range. 相似文献
