Güímar and la Orotava mega-landslides (Tenerife) and Tsunamis deposits in Canary Islands

[EN] More than 20 mega-landslides have been described in the Canary Islands affecting the flanks of the volcanic edifices. Güímar and La Orotava landslides, in Tenerife, are two exceptional cases due to their huge dimensions and outstanding geomorphological features. The estimated volume of these landslides exceed tens of cubic km. Tsunami deposits have been also identified in some of the islands of the archipelago probably associated to the large landslides of the islands flanks. An investigation has been carried out to explain the causes of these large instability processes and their failure mechanisms.

Public Risk Interpretation and Community Resilience Planning: A Case Study in Aberdeen, Washington

Thesis (Master's)--University of Washington, 2016-06

Failure Mechanisms and Local Scour at Coastal Structures induced by Tsunamis

On March 11 2011, an exceptionally large tsunami event was triggered by a massive earthquake offshore, the northeast coast of Japan, which affected coastal infrastructure such as seawalls, coastal dikes and breakwaters in the Tohoku region. Such infrastructure was built to protect against the Level 1 tsunamis that previously hit the region, but not for events as significant as the 2011 Tohoku tsunami, which was categorized as a Level 2 tsunami [Shibayama et al. 2013]. The failure mechanisms of concrete-armoured dikes, breakwaters and seawalls due to Level 2 tsunamis are still not fully understood by researchers and engineers. This paper investigates the failure modes and mechanisms of damaged coastal structures in Miyagi and Fukushima Prefectures, following the authors' post-disaster field surveys carried out between 2011 and 2013. Six significant failure mechanisms were identified for the coastal dikes and seawalls affected by this tsunami: 1) Leeward toe scour failure, 2) Crown armour failure, 3) Leeward slope armour failure, 4) Seaward toe and armour failure, 5) Overturning failure, and 6) Parapet wall failure, in which leeward toe scour being recognized as the major failure mechanism in most surveyed locations. The authors also propose a simple practical mathematical model for predicting the scour depth at the leeward toe of the coastal dikes, by considering the effects of the tsunami hydrodynamics, the soil properties and the type of structure. The key advantage of this model is that it depends entirely on quantities that are measurable in the field. Furthermore this model was further refined by conducting a series of hydraulic model experiments aimed to understand the governing factors of the leeward toe scour failure. Finally, based on the results obtained, key recommendations are given for the design of resilient coastal defence structures that can survive a level 2 tsunami event.

Understanding stakeholder participation in post-disaster recovery (case study: Nagapattinam, India)

Stakeholder participation is widely acknowledged as a critical component of post-disaster recovery because it helps create a shared understanding of local hazard risk and vulnerability, improves recovery and mitigation decision efficacy, and builds social capital and local resilience to future disasters. But approaches commonly used to facilitate participation and empower local communities depend on lengthy consensus-building processes which is not conducive to time-constrained post-disaster recovery. Moreover, these approaches are often criticized for being overly technocratic and ignoring existing community power and trust structures. Therefore, there is a need for more nuanced, analytical and applied research on stakeholder participation in planning for post-disaster recovery. This research examines participatory behavior of three stakeholder groups (government agencies, non-local non-government organizations, local community-based organizations) in three coastal village communities of Nagapattinam (India) that were recovering from the 2004 Indian Ocean tsunami. The study found eight different forms of participation and non-participation in the case study communities, ranging from 'transformative' participation to 'marginalized' non-participation. These forms of participation and non-participatory behavior emanated from the negotiation of four factors, namely stakeholder power, legitimacy, trust, and urgency for action. The study also found that the time constraints and changing conditions of recovery pose particular challenges for how these factors operated on the ground and over the course of recovery. Finally, the study uses these insights to suggest four strategies for recovery managers to use in the short- and long-term to facilitate more effective stakeholder participation in post-disaster recovery.

Rebuilding a Better Response

What is one thing in the world that we have little control over? Mother Nature. We as humans have tried to alter our natural environment countless times, and she has fought back twice as strong, leaving trails of devastation behind. The number of natural disasters has drastically increased, especially in the Southeast Asian region. The aftermath of a tsunami has left a large number of people homeless and lives forever changed. The current recovery process is chaotic and leaves affected individuals stranded without the means of rebuilding for long periods of time. This thesis aims to re-evaluate the recovery relief procedures and provide a better means of rebuilding their lives and community.

Probabilistic Imaging and Dynamic Modeling of Earthquake Source Processes

Investigation of large, destructive earthquakes is challenged by their infrequent occurrence and the remote nature of geophysical observations. This thesis sheds light on the source processes of large earthquakes from two perspectives: robust and quantitative observational constraints through Bayesian inference for earthquake source models, and physical insights on the interconnections of seismic and aseismic fault behavior from elastodynamic modeling of earthquake ruptures and aseismic processes.

To constrain the shallow deformation during megathrust events, we develop semi-analytical and numerical Bayesian approaches to explore the maximum resolution of the tsunami data, with a focus on incorporating the uncertainty in the forward modeling. These methodologies are then applied to invert for the coseismic seafloor displacement field in the 2011 Mw 9.0 Tohoku-Oki earthquake using near-field tsunami waveforms and for the coseismic fault slip models in the 2010 Mw 8.8 Maule earthquake with complementary tsunami and geodetic observations. From posterior estimates of model parameters and their uncertainties, we are able to quantitatively constrain the near-trench profiles of seafloor displacement and fault slip. Similar characteristic patterns emerge during both events, featuring the peak of uplift near the edge of the accretionary wedge with a decay toward the trench axis, with implications for fault failure and tsunamigenic mechanisms of megathrust earthquakes.

To understand the behavior of earthquakes at the base of the seismogenic zone on continental strike-slip faults, we simulate the interactions of dynamic earthquake rupture, aseismic slip, and heterogeneity in rate-and-state fault models coupled with shear heating. Our study explains the long-standing enigma of seismic quiescence on major fault segments known to have hosted large earthquakes by deeper penetration of large earthquakes below the seismogenic zone, where mature faults have well-localized creeping extensions. This conclusion is supported by the simulated relationship between seismicity and large earthquakes as well as by observations from recent large events. We also use the modeling to connect the geodetic observables of fault locking with the behavior of seismicity in numerical models, investigating how a combination of interseismic geodetic and seismological estimates could constrain the locked-creeping transition of faults and potentially their co- and post-seismic behavior.

A mobile health network disaster management system

A common occurrence in almost all full-scale natural disasters is the rapid destruction of the telecommunication infrastructure as the inevitable unfolds, which tends to halt the necessary communications between the humanitarian operators and the people in need. In such scenarios, the deployment of wireless networks would provide fast and temporary remedies, however these networks normally do not provide services to the end-users and ordinary people, instead they provide connectivity between groups of end-users administered by a local service provider. From a range of services provided to the end-users by the humanitarian operators, healthcare is by far the top priority. This is considered through the utilization of smartphones in a Mobile Health (mHealth) perspective, which is an emerging concept for monitoring and tracking end-user health conditions. This article considers an mHealth system used in a tsunami-stricken disaster scenario, including a discussion on the most recent advances of Device to Device (D2D) and LTE-Direct technologies.

Incidencia del proyecto “ASEAN community” en el desarrollo humano de Tailandia (2004-2014)

Esta investigación se interesa en evaluar los logros y retos que ha presentado el proyecto ASEAN Community en cada una de sus tres áreas de acción (Comunidad económica, comunidad de política y seguridad, y comunidad socio-cultural) ante su aplicación en Tailandia. De esta manera, se busca analizar la incidencia que ha tenido el proyecto en el Desarrollo Humano de Tailandia durante el periodo 2004-2014. A través del análisis del estatus actual a la luz del concepto de libertades instrumentales se realiza la evaluación de los resultados de los proyectos y su conveniencia o no para el desarrollo humano de la sociedad tailandesa.

GEOGRAFÍA, CONSTRUCCIÓN DE TERRITORIO Y JUSTICIA SOCIAL: PRÁCTICAS ESPACIALES, GÉNERO Y DESARROLLO EN CHILE

Desde la Geografía Humana, este artículo intenta visibilizar la forma en que los distintos agentes y actores locales participan en la producción y construcción de territorios, proceso que se hizo explícito en el contexto chileno post-terremoto a nivel local y regional. Planteamos la posibilidad de una (re)configuración espacial de las zonas más afectadas por el megasismo y tsunami que sacudió a Chile el 27 de febrero de 2010 a partir de una perspectiva local, indagando en el territorio comprendido como escenario de la comunidad, que al mismo tiempo da sustento y contenido a la misma. La ilustración empírica de nuestro estudio la encontramos en el estudio de las redes sociales puestas en marcha a partir de la catástrofe, las que funcionaron como puente entre áreas rurales, urbanas y costeras con el propósito de contribuir a satisfacer necesidades primarias en emergencia. Desde una perspectiva local, grupos de campesinos/as, pescadores artesanales y habitantes de áreas semi-urbanas de la Región del Bio Bío, presentan propuestas de proyectos territorializados que apuestan por la construcción de localidades sustentables económica, social, ambiental y culturalmente. Proyectos relacionados con la agroecología y el turismo agroecológico sirven como herramientas revitalizadoras de la sociedad local de una forma integral, entre otras formas, a través de la creación de nuevos trabajos sustentables. En este contexto, la asociatividad del mundo académico con la sociedad civil organizada, conformarían una alianza estratégica que permitiría el intercambio de conocimientos y saberes, base fundamental del enfoque Investigación-Acción Participativa que sustenta nuestro trabajo.