A5040222957- earthquake and tectonic studies
- Earthquake and Tsunami Effects
- Coastal and Marine Dynamics
- Tropical and Extratropical Cyclones Research
- Geological and Geophysical Studies
- Seismology and Earthquake Studies
- Ocean Waves and Remote Sensing
- Geology and Paleoclimatology Research
- Methane Hydrates and Related Phenomena
- Marine and environmental studies
- Earthquake Detection and Analysis
- High-pressure geophysics and materials
- Maritime and Coastal Archaeology
- Geological formations and processes
- Geological and Geochemical Analysis
- Landslides and related hazards
- Oceanographic and Atmospheric Processes
- Disaster Management and Resilience
- Geophysics and Gravity Measurements
- Fluid Dynamics Simulations and Interactions
- Seismic Waves and Analysis
- Geological and Geophysical Studies Worldwide
- Wave and Wind Energy Systems
- Seismic Imaging and Inversion Techniques
- Flood Risk Assessment and Management
University of Southern California
2014-2024
Academy of Athens
2020-2023
National Observatory
2023
National Observatory of Athens
2023
Technical University of Crete
2011-2022
Southern California University for Professional Studies
2001-2019
LAC+USC Medical Center
2019
Hellenic Centre for Marine Research
2011-2013
Viterbo University
2013
FORTH Institute of Applied and Computational Mathematics
2009-2011
This is a study of the runup solitary waves on plane beaches. An approximate theory presented for non-breaking and an asymptotic result derived maximum waves. A series laboratory experiments described to support theory. It shown that linear predicts satisfactorily, nonlinear describes climb equally well. Different regimes are found exist breaking criterion determining whether wave will break as it climbs up sloping beach, different apply during rundown. These results used explain some...
A numerical solution for the 2 + 1 (long-shore and onshore propagation directions time) nonlinear shallow-water wave equations, without friction factors or artificial viscosity is presented. The models use a splitting method to generate two problems, one in other long-shore direction. Both are solved characteristic form using of characteristics. shoreline algorithm implemented, which generalization earlier used code VTCS-2. model validated large-scale laboratory data from solitary...
This is a study of the interactions solitary waves climbing up circular island. A series large-scale laboratory experiments with different incident height-to-depth ratios and crest lengths described. Detailed two-dimensional run-up height measurements time histories surface elevations around island are presented. numerical model based on shallow-water wave equations including runup calculations was developed. Numerical predictions agreed very well data used to trapping effect slope. Under...
The origin of the Papua New Guinea tsunami that killed over 2100 people on 17 July 1998 has remained controversial, as dislocation sources based parent earthquake fail to model its extreme run–up amplitude. generation tsunamis by submarine mass failure had been considered a rare phenomenon which aroused virtually no attention in terms hazard mitigation. We report recently acquired high–resolution seismic reflection data yield new images large underwater slump, coincident with photographic...
The first probabilistic tsunami flooding maps have been developed. methodology, called hazard assessment (PTHA), integrates inundation modeling with methods of seismic (PSHA). Application the methodology to Seaside, Oregon, has yielded estimates spatial distribution 100‐ and 500‐year maximum amplitudes, i.e., amplitudes 1% 0.2% annual probability exceedance. 100‐year is generated most frequently by far‐field sources in Alaska‐Aleutian Subduction Zone characterized that do not exceed 4 m, an...
On March 11, 2011, a magnitude M w 9.0 earthquake occurred off the coast of Japan's Tohoku region causing catastrophic damage and loss life. The tsunami flow velocity analysis focused on two survivor videos recorded from building rooftops at Kesennuma Bay along Sanriku coast. A terrestrial laser scanner was deployed locations eyewitness video recordings. current velocities through are determined in four step process. LiDAR point clouds used to calibrate camera fields view real world...
Tsunami science has evolved differently from research on other extreme natural hazards, primarily because of the unavailability until recently instrumental recordings tsunamis in open ocean. Here, progress towards developing tsunami inundation modelling tools for use forecasting is discussed historically perspective hydrodynamics. The state-of-knowledge before 26 December 2004 described. Remaining aspects future are identified. One, validated models need to be further developed through...
In response to the 26 December 2004 tsunami, a survey team of scientists was dispatched Sri Lanka. Measurements made by show that tsunami elevation and runup ranged from 5 12 meters. Eyewitnesses report up three separate waves attacked coast, with second or third generally largest. Our conclusion stresses importance education: Residents basic knowledge tsunamis, as well an understanding how environmental modifications will affect overland flow, are paramount saving lives minimizing destruction.
Anecdotal reports of tsunamis climbing up coastlines have often described the shoreline receding significantly before tsunami waves run-up on beach. These are caused by tsunamigenic earthquakes close to shoreline, when generated wave does not sufficient propagation distance evolve into leading-elevation or a series solitary waves. Yet all previous investigations modelled periodic which initially only In our studies these shorelines, we found class N -shaped with very interesting and...
To study the waves and runup/rundown generated by a sliding mass, numerical simulation model, based on large-eddy-simulation (LES) approach, was developed. The Smagorinsky subgrid scale model employed to provide turbulence dissipation volume of fluid (VOF) method used track free surface shoreline movements. A algorithm for describing motion mass also implemented.To validate we conducted set large-scale experiments in wave tank 104m long, 3.7m wide 4.6m deep with plane slope (1:2) located at...
We present a variable grid finite-differences approximation of the characteristic form shallow-water-wave equations without artificial viscosity or friction factors to model propagation and runup one-dimensional long waves, referred as VTCS-2. apply our method in calculation evolution breaking nonbreaking waves on sloping beaches. compare computational results with analytical solutions, other numerical computations laboratory data for solitary waves. find that describes very well, even when...
We present numerical simulations of tsunami run-up in the near field for a data set 72 models sources, involving both seismic dislocations and landslides. By varying one by parameters describing source receiving beach, we are able to separate their individual influence on amplitude distribution run-up, which characterize forming several dimensionless parameters, principally ratio I2 its maximum lateral extent along beach. find that remains less than 10−4 dislocation sources but is greater...
We evaluate far-field tsunami hazard in the Indian Ocean Basin based on hydrodynamic simulations of ten case studies possible mega earthquakes at major seismic zones surrounding basin. They represent worst-case scenarios rupture along full extent seismogenic faults having supported large historical record. In a series numerical experiments which source parameters 2004 Sumatra are allowed to vary one by one, while keeping moment and fault orientation unchanged, we document that main patterns...
The M w 7.8 October 2010 Mentawai, Indonesia, earthquake was a “tsunami earthquake,” rare type of that generates tsunami much larger than expected based on the seismic magnitude. It produced locally devastating tsunami, with runup commonly in excess 6 m. We examine this event using combination high‐rate GPS data, from instruments located nearby islands, and field survey. displacement time series are deficient high‐frequency energy, show small coseismic displacements (<22 cm horizontal...
An International Tsunami Survey Team (ITST) consisting of scientists from the United States, New Zealand, and Sri Lanka evaluated impacts 26 December 2004 transoceanic tsunami in two weeks after event. runup height, inundation distance, morphological changes, sedimentary characteristics deposits were recorded analyzed along southwest east coasts country. Preliminary results show how local topography bathymetry controlled limits associated damage to infrastructure. The largest wave height...
The tsunami of 26th December 2004 severely affected Banda Aceh along the North tip Sumatra (Indonesia) at a distance 250 km from epicenter magnitude 9.0 earthquake. This flow velocity analysis focused on two survivor videos recorded within more than 3 open ocean. exact locations eyewitness video recordings were revisited by survey team between February 22 and 25, 2005 to record camera calibration ground control points. motion during was determined. individual images rectified with direct...
The 17 July 2006 magnitude M w 7.8 earthquake off the south coast of western Java, Indonesia, generated a tsunami that effected over 300 km coastline and killed more than 600 people, with locally focused runup heights exceeding 20 m. This slow was hardly felt on wind waves breaking masked any preceding withdrawal water from shoreline, making this difficult to detect before impact. An International Tsunami Survey Team deployed within one week investigation covered coastline. Measured run‐up...
We conduct a comprehensive study of the Amorgos, Greece earthquake and tsunami 1956 July 09, largest such event in Aegean Sea 20th century. Systematic relocation main shock 34 associated events defines rupture area measuring 75 × 40 km. The use Preliminary Determination Focal Mechanism algorithm resolves longstanding controversy about focal geometry event, yielding normal faulting mechanism along plane dipping to southeast, which expresses extensional tectonics back arc behind Hellenic...
The development, testing, and implementation of a real-time tsunami forecast model, the method splitting (MOST), is described. MOST now used as an operational model for National Oceanic Atmospheric Administration's Tsunami Warning System, hazard assessment tool in United States many countries around world. Every step development marked new scientific challenges, improvements technological computational capabilities, demands engineering mitigation communities applied benchmark modeling tools...
The August 8, 2023R Lahaina fire refocused attention on wildfires, public alerts, and emergency management. Wildfire risk is the rise, precipitated through a combination of climate change, increased development in wildland-urban interface (WUI), decades unmitigated biomass accumulation forests, long history emphasis suppression over hazard mitigation. Stemming tide wildfire death destruction will involve bringing together diverse scientific disciplines into policy. Renewed needed alerts...