GROUND DEFORMATION STUDIES AND EVACUATION BEHAVIOR DURING ERUPTIONS AT GUATEMALAN VOLCANOES

Volcanic eruptions can be an especially problematic hazard when considering the uncertainty in eruption timing and magnitude coupled with challenges associated with delivering warnings to remote areas and facilitating effective evacuations. The hazards presented by Guatemala’s active volcanoes demand enhanced monitoring capabilities and instrumentation infrastructure. Strengthening the link between the physical and social sciences should lead to more accurate, reliable, and timely hazard information to the people living in proximity to the volcano and facilitate rational decisions and actions that reduce their level of risk. While there is no one single technique that can provide unambiguous diagnostics about the timing, behavior, and outcome of a volcanic eruption, the use of GPS geodesy can provide valuable insight into the internal dynamics of a volcano allowing for enhanced interpretation of unrest signals that can be relayed to crisis management officials. The 2010 eruption of Pacaya lead to evacuations of more than 2500 people and resulted in damage and destruction to hundreds of homes. During this period of unrest, Pacaya was a poorly monitored volcano with little available quantitative geophysical data. However, despite a pronounced increase in activity prior to the eruption, and the heightened threat of injury or death during the eruption, many residents in communities surrounding the volcano chose to stay in their home throughout the eruptive crisis. Part of this research presents measurements from a campaign GPS network at Pacaya volcano, combined with InSAR data that reveals a large downward vertical and outward horizontal deformation signal at several locations around the volcano associated with two eruptive periods. We invert the available geodetic data to model the magma plumbing system and produce analytical models, which suggest that deformation was dominated by inflation of a sub-vertical dike high within the edifice while deflation of one or two deeper, spherical sources embedded below the edifice occurred during part of the observation period. The second part of this research seeks to understand why some chose to stay in harm’s way. Using data obtained from a door-to-door survey we found that evacuation behavior was strongly influenced by one’s exposure to and perception of the hazards as well as their perception of readiness. We also found that future intention to evacuate is strongly influenced by prior evacuation experience, perception of home vulnerability and warning messages. The research presented in this dissertation integrates geophysics and social vulnerability research with the aim to better understand magmatic system dynamics and associated hazards in volcanic regions in an effort to improve warning messages and evacuation behavior

Differential GPS as a monitoring tool on Volcano Santa Ana (Illamatepec) and the Coatepeque Caldera, El Salvador

We used differential GPS measurements from a 13 station GPS network spanning the Santa Ana Volcano and Coatepeque Caldera to characterize the inter-eruptive activity and tectonic movements near these two active and potentially hazardous features. Caldera-forming events occurred from 70-40 ka and at Santa Ana/Izalco volcanoes eruptive activity occurred as recently as 2005. Twelve differential stations were surveyed for 1 to 2 hours on a monthly basis from February through September 2009 and tied to a centrally located continuous GPS station, which serves as the reference site for this volcanic network. Repeatabilities of the averages from 20-minute sessions taken over 20 hours or longer range from 2-11 mm in the horizontal (north and east) components of the inter-station baselines, suggesting a lower detection limit for the horizontal components of any short-term tectonic or volcanic deformation. Repeatabilities of the vertical baseline component range from 12-34 mm. Analysis of the precipitable water vapor in the troposphere suggests that tropospheric decorrelation as a function of baseline lengths and variable site elevations are the most likely sources of vertical error. Differential motions of the 12 sites relative to the continuous reference site reveal inflation from February through July at several sites surrounding the caldera with vertical displacements that range from 61 mm to 139 mm followed by a lower magnitude deflation event on 1.8-7.4 km-long baselines. Uplift rates for the inflationary period reach 300 mm/yr with 1σ uncertainties of +/- 26 – 119 mm. Only one other station outside the caldera exhibits a similar deformation trend, suggesting a localized source. The results suggest that the use of differential GPS measurements from short duration occupations over short baselines can be a useful monitoring tool at sub-tropical volcanoes and calderas

IWB: Beiträge zur Wirtschaftspolitik

Die "Beiträge" sind ein Forum zur Diskussion aktueller wirtschaftspolitischer Problemfelder im In- und Ausland. Sie sollen Aspekte der Wirtschaftspolitik beleuchten, die von der Praxis und ihren akademischen Beratern vernachlässigt werden und anfechtbaren Positionen aus Praxis und Wissenschaft begründet entgegentreten

Endogeneity and non-response bias in treatment evaluation - nonparametric identification of causal effects by instruments

This paper proposes a nonparametric method for evaluating treatment effects in the presence of both treatment endogeneity and attrition/non-response bias, using two instrumental variables. Making use of a discrete instrument for the treatment and a continuous instrument for nonresponse/attrition, we identify the average treatment effect on compliers as well as the total population and suggest non- and semiparametric estimators. We apply the latter to a randomized experiment at a Swiss University in order to estimate the effect of gym training on students› selfassessed health. The treatment (gym training) and attrition are instrumented by randomized cash incentives paid out conditional on gym visits and by a cash lottery for participating in the follow-up survey, respectively

Phylogenetics from paralogs

Motivation: Sequence-based phylogenetic approaches heavily rely on initial data sets to be composed of orthologous sequences only. Paralogs are treated as a dangerous nuisance that has to be detected and removed. Recent advances in mathematical phylogenetics, however, have indicated that gene duplications can also convey meaningful phylogenetic information provided orthologs and paralogs can be distinguished with a degree of certainty. Results: We demonstrate that plausible phylogenetic trees can be inferred from paralogy information only. To this end, tree-free estimates of orthology, the complement of paralogy, are first corrected to conform cographs and then translated into equivalent event-labeled gene phylogenies. A certain subset of the triples displayed by these trees translates into constraints on the species trees. While the resolution is very poor for individual gene families, we observe that genome-wide data sets are sufficient to generate fully resolved phylogenetic trees of several groups of eubacteria. The novel method introduced here relies on solving three intertwined NP-hard optimization problems: the cograph editing problem, the maximum consistent triple set problem, and the least resolved tree problem. Implemented as Integer Linear Program, paralogy-based phylogenies can be computed exactly for up to some twenty species and their complete protein complements. Availability:The ILP formulation is implemented in the Software ParaPhylo using IBM ILOG CPLEX (TM) Optimizer 12.6 and is freely available from http://pacosy.informatik.uni-leipzig.de/paraphyl

Functional Analysis of Components Manufactured by a Sheet-Bulk Metal Forming Process

Due to rising demands regarding the functionality and load-bearing capacity of functional components such as synchronizer rings in gear systems, conventional forming operations are reaching their limits with respect to formability and efficiency. One way to meet these challenges is the application of the innovative process class of sheet-bulk metal forming (SBMF). By applying bulk forming operations to sheet metal, the advantages of both process classes can be combined, thus realizing an optimized part weight and an adapted load-bearing capacity. Different approaches to manufacturing relevant part geometries were presented and evaluated regarding the process properties and applicability. In this contribution, a self-learning engineering workbench was used to provide geometry-based data regarding a novel component geometry with circumferential involute gearing manufactured in an SBMF process combination of deep drawing and upsetting. Within the comprehensive investigations, the mechanical and geometrical properties of the part were analyzed. Moreover, the manufactured components were compared regarding the increased fatigue strength in cyclic load tests. With the gained experimental and numerical data, the workbench was used for the first time to generate the desired component as a CAD model, as well as to derive design guidelines referring to the investigated properties and fatigue behavior