Geology topics

K. Jaiswal

Publications and source records attributed to K. Jaiswal.

6 recordsLinked to original sources

USGS2012

Post-earthquake building safety assessments for the Canterbury Earthquakes

This paper explores the post-earthquake building assessment program that was utilized in Christchurch, New Zealand following the Canterbury Sequence of earthquakes beginning with the Magnitude (M w .) 7.1 Darfield event in September 2010. The aftershocks or triggered events, two of which exceeded M w 6.0, continued with events in February and June 2011 causing the greatest amount of damage. More than 70,000 building safety assessments were completed following the February event. The timeline and assessment procedures will be discussed including the use of rapid response teams, selection of indicator buildings to monitor damage following aftershocks, risk assessments for demolition of red-tagged buildings, the use of task forces to address management of the heavily damaged downtown area and the process of demolition. Through the post-event safety assessment program that occurred throughout the Canterbury Sequence of earthquakes, many important lessons can be learned that will benefit future response to natural hazards that have potential to damage structures.

Conference Paper↗

USGS2012

Spatial aspects of building and population exposure data and their implications for global earthquake exposure modeling

This paper discusses spatial aspects of the global exposure dataset and mapping needs for earthquake risk assessment. We discuss this in the context of development of a Global Exposure Database for the Global Earthquake Model (GED4GEM), which requires compilation of a multi-scale inventory of assets at risk, for example, buildings, populations, and economic exposure. After defining the relevant spatial and geographic scales of interest, different procedures are proposed to disaggregate coarse-resolution data, to map them, and if necessary to infer missing data by using proxies. We discuss the advantages and limitations of these methodologies and detail the potentials of utilizing remote-sensing data. The latter is used especially to homogenize an existing coarser dataset and, where possible, replace it with detailed information extracted from remote sensing using the built-up indicators for different environments. Present research shows that the spatial aspects of earthquake risk computation are tightly connected with the availability of datasets of the resolution necessary for producing sufficiently detailed exposure. The global exposure database designed by the GED4GEM project is able to manage datasets and queries of multiple spatial scales.

Natural Hazards↗

USGS2012

GEM Basic Building Taxonomy (Version 1.0)

This report documents the development of Global Earthquake Model (GEM) Basic Building Taxonomy and it also provides version 1.0 of this Taxonomy for its immediate application within GEM Physical Risk projects. Criteria for development of the GEM Building Taxonomy required that the Taxonomy be relevant to seismic performance of different construction types; be comprehensive yet simple; be collapsible; be adhering to principles that are familiar to the range of users; and ultimately be extensible to non-buildings and other hazards. The taxonomy is organized as a series of expandable tables, which contain information pertaining to various building attributes. Each attribute describes a specific characteristic that could potentially affect the seismic performance of a building. This report describes the structure and the content of the Basic Building Taxonomy, which consists of eight basic attributes, in detail. These attributes were selected after a series of interactions/discussions with all the GEM Physical Risk Global Component project teams. In addition, we also tried to gather feedback from a number of participants outside the GEM Risk Consortium group. The Basic Taxonomy attributes discussed in this report are: material; lateral load-resisting system; roof; floor; building height; date of construction; structural irregularity, and occupancy. A future Detailed Building Taxonomy will provide more details related to certain aforementioned attributes in the Basic Building Taxonomy. As well, it will also include additional attributes that are necessary for assessing building vulnerability using analytical procedures. The report also illustrates the practical use of the proposed GEM Basic Building Taxonomy by discussing example case studies, wherein the building-specific characteristics are mapped directly using GEM Taxonomic attributes and a simple taxonomic string is constructed for that building. The building taxonomy data model is highly flexible and it can be easily incorporated within the relational database architecture. Due to its ability to represent building typologies using a shorthand form, it is also possible to use this taxonomy for non-database applications. Key terms in the taxonomy are explained in an online glossary, which provides both text and graphic descriptions for the attributes and their details.

Report↗

USGS2011

Developing empirical collapse fragility functions for global building types

Building collapse is the dominant cause of casualties during earthquakes. In order to better predict human fatalities, the U.S. Geological Survey’s Prompt Assessment of Global Earthquakes for Response (PAGER) program requires collapse fragility functions for global building types. The collapse fragility is expressed as the probability of collapse at discrete levels of the input hazard defined in terms of macroseismic intensity. This article provides a simple procedure for quantifying collapse fragility using vulnerability criteria based on the European Macroseismic Scale (1998) for selected European building types. In addition, the collapse fragility functions are developed for global building types by fitting the beta distribution to the multiple experts’ estimates for the same building type (obtained from EERI’s World Housing Encyclopedia (WHE)-PAGER survey). Finally, using the collapse probability distributions at each shaking intensity level as a prior and field-based collapse-rate observations as likelihood, it is possible to update the collapse fragility functions for global building types using the Bayesian procedure.

Earthquake Spectra↗

USGS2010

PAGER--Rapid assessment of an earthquakes impact

PAGER (Prompt Assessment of Global Earthquakes for Response) is an automated system that produces content concerning the impact of significant earthquakes around the world, informing emergency responders, government and aid agencies, and the media of the scope of the potential disaster. PAGER rapidly assesses earthquake impacts by comparing the population exposed to each level of shaking intensity with models of economic and fatality losses based on past earthquakes in each country or region of the world. Earthquake alerts--which were formerly sent based only on event magnitude and location, or population exposure to shaking--now will also be generated based on the estimated range of fatalities and economic losses.

Fact Sheet↗

USGS2008

Development of the U.S. Geological Survey's PAGER system (Prompt Assessment of Global Earthquakes for Response)

The Prompt Assessment of Global Earthquakes for Response (PAGER) System plays a primary alerting role for global earthquake disasters as part of the U.S. Geological Survey’s (USGS) response protocol. We provide an overview of the PAGER system, both of its current capabilities and our ongoing research and development. PAGER monitors the USGS’s near real-time U.S. and global earthquake origins and automatically identifies events that are of societal importance, well in advance of ground-truth or news accounts. Current PAGER notifications and Web pages estimate the population exposed to each seismic intensity level. In addition to being a useful indicator of potential impact, PAGER’s intensity/exposure display provides a new standard in the dissemination of rapid earthquake information. We are currently developing and testing a more comprehensive alert system that will include casualty estimates. This is motivated by the idea that an estimated range of possible number of deaths will aid in decisions regarding humanitarian response. Underlying the PAGER exposure and loss models are global earthquake ShakeMap shaking estimates, constrained as quickly as possible by finite-fault modeling and observed ground motions and intensities, when available. Loss modeling is being developed comprehensively with a suite of candidate models that range from fully empirical to largely analytical approaches. Which of these models is most appropriate for use in a particular earthquake depends on how much is known about local building stocks and their vulnerabilities. A first-order country-specific global building inventory has been developed, as have corresponding vulnerability functions. For calibrating PAGER loss models, we have systematically generated an Atlas of 5,000 ShakeMaps for significant global earthquakes during the last 36 years. For many of these, auxiliary earthquake source and shaking intensity data are also available. Refinements to the loss models are ongoing. Fundamental to such an alert system, we are also developing computational and communications infrastructure for rapid and robust operations and worldwide notifications. PAGER’s methodologies and datasets are being developed in an open environment to support other loss estimation efforts and provide avenues for outside collaboration and critique.

Conference Paper↗