Wilfried Strauch

• PhD
• Advisor on Geosciences at Instituto Nicaraguense de Estudios Territoriales

Central America is a seismically active region located in a tectonic setting dominated by the subduction zone between the Cocos and Caribbean plates, transform boundaries between the North American and Caribbean plates, and local or crustal faulting with some of the most important fault systems aligned with the volcanic arc. Combining seismic data...

Trench‐parallel translation of the Central American Forearc (CAFA) is the result of strain partitioning along the Cocos and Caribbean (CA) convergent margin. Unlike the tectonics of northwestern Costa Rica and El Salvador, CAFA‐CA relative motion in Nicaragua is not accommodated on margin‐parallel fault systems. Rather, the northwest‐trending dextr...

An international, multidisciplinary research group is proposing the “NICA-BRIDGE” drilling project, within the framework of the International Continental Scientific Drilling Program (ICDP). The project goal is to conduct scientific drilling in Lake Nicaragua and Lake Managua (Nicaragua, Central America) to obtain long lacustrine sediment records to...

Strain partitioning in oblique convergent margins results in margin‐parallel shear in the overriding plate. Margin‐parallel shear is often accommodated by margin‐parallel strike‐slip faults proximal to active volcanic arcs. Along the Nicaraguan segment of the Central American Forearc (CAFA) in the Cocos‐Caribbean plate convergent margin, there are...

Gas and particulate matter (PM) emissions from Masaya volcano, Nicaragua, cause substantial regional volcanic air pollution (VAP). We evaluate the suitability of low-cost SO2 and PM sensors for a continuous air-quality network. The network was deployed for six months in five populated areas (4-16 km from crater). The SO2 sensors failed and recorded...

Gas and particulate matter (PM) emissions from Masaya volcano, Nicaragua, cause substantial regional volcanic air pollution (VAP). We evaluate the suitability of low-cost SO2 and PM sensors for a continuous air-quality network. The network was deployed for six months in five populated areas (4–16 km from crater). The SO2 sensors failed and recorded...

Many of Earth's volcanoes experience well‐defined states of “quiescence” and “unrest,” with unrest occasionally culminating in eruption. Some volcanoes, however, experience an unusually protracted (i.e., decades‐long) period of noneruptive unrest and are thus categorized as “persistently restless volcanoes” (PRVs). The processes that drive persiste...

Since 2016 SED and INETER are working jointly to build a prototype earthquake early warning and earthquake rapid information system for Nicaragua and also potentially for other countries in Central America (CAM). The project primarily requires implementing and testing state-of-the-art software and standard seismological services / tools in Nicaragu...

Since the end of 2013, the region around the volcanoes Masaya and Momotombo, which includes Nicaraguan capital Managua, has shown unusually high seismic and volcanic activitiy. On April 10, 2013, a M6.3 earthquake occured near Momotombo volcano followed by intense aftershock activitiy and a migration of seismicity towards Managua. In the following...

In January of 2018, we finished to install new hardware and software at the Central American Tsunami Advisory Center (CATAC), established at INETER in Nicaragua. CATAC is the most recent tsunami warning center integrating decision support and warning dissemination based on the SeisComP3 framework. SeisComP3 is a seismological software package used...

The Nicaraguan Institute for Terrestrial Studies (Instituto Nicaraguense de Estudios Territoriales, INETER) received a grant to develop a mirror data center to host and serve COCONet data and metadata from UNAVCO and serve as a geodetic seamless archive center through web services (GSAC-WS). INETER, headquartered in Managua, Nicaragua is serving th...

In 2015, the Central American countries (Guatemala, El Salvador, Honduras, Nicaragua, Costa Rica and Panama) agreed to establish a Central American Tsunami Advisory Center (CATAC) at INETER in Managua, Nicaragua. This proposal was also approved by the Intergovernmental Oceanographic Committee (IOC) of UNESCO and the Intergovernmental Coordination G...

In the last years, the Monitoring and Early Warning Center for Earthquakes and Tsunamis at INETER, Nicaragua, has developed rapidly due to new responsibilities INETER acquired at national and international level. In 2015, it became home of the Central American Tsunami Advisory Center CATAC). In 2016, INETER started a cooperation with the Swiss Seis...

This study was done in the framework of the project on the Reinforcement of the Central American Tsunami Advisory Center (CATAC) to be established at INETER in Managua, Nicaragua. To emit reliable and sufficiently fast tsunami services for local tsunamis it is necessary to determine, in near real time, the appropriate fault model needed for the tsu...

We report on seismic and tsunami monitoring and early warning systems in Nicaragua and Central America, regions that are bordered by plate boundaries and subduction zones with related high seismic and tsunami risks. These systems were established in Nicaragua only after big earthquake and tsunami disasters (that took place in Managua in 1972 and th...

Citizens of Central America are exposed to damaging shallow crustal earthquakes and tsunamigenic subduction zone earthquakes, in addition to living amongst multiple active volcanoes. In response to these hazards, most countries in the region operate relatively sophisticated, dense seismic networks, and data is openly shared in the cross border ‘Reg...

Earthquake early warning (EEW) systems aim at providing real-time estimates of event parameters or expected ground motion over wide ranges of source dimensions. In 2016, SED and INETER started a joint project funded by the Swiss Development Agency to assess the feasibility of EEW in the Nicaragua in particular and in Central America in general. The...

In the past three years, the region around the volcanoes Masaya and Momotombo, which includes Nicaraguanscapital Managua, has shown an unusually high seismic and volcanic activity.On April 10, 2014, a M6.3 earthquake occurred near Momotombo volcano followed by intense aftershockactivity and a migration of seismicity towards Managua. In the followin...

Earthquake early warning (EEW) systems aim at providing fast and accurate estimates of event parameters or local ground shaking over wide ranges of source dimensions and epicentral distances. The Swiss Seismological Service (SED) has integrated EEW solutions into the SeisComP3 (SC3) professional earthquake monitoring software. VS(SC3) provides fast...

Central America is a small and culturally homogeneous region that, since the 1990s, has experienced economic and political integration of its six countries, which share the same threats of volcanic eruptions, disastrous earthquakes and tsunamis. The Pacific coastline of 1700 km is common for Guatemala, El Salvador, Honduras, Nicaragua, Costa Rica a...

In the past three years, the region around the volcanoes Masaya and Momotombo, which includes Nicaraguans capital Managua, has shown an unusually high seismic and volcanic activity. On April 10, 2014, a M6.3 earthquake occurred near Momotombo volcano followed by intense aftershock activity and a migration of seismicity towards Managua. In the follo...

We report about the status and the progress of the Nicaraguan Seismic Network. The Network is used for seismic and volcano monitoring, tsunami warning and lahars and landslide warning. The network counts around 100 stations. Many stations are multisensor stations and count also with webcams, continuous GPS or other sensors. All field stations are d...

We will provide an analysis of the scope for Earthquake Early Warning (EEW) in Nicaragua and the Central American region based on 1) The existing seismic network, data sharing and communications practice, data processing and 2) The existing network with assumed improved communications and EEW algorithms that may become available. This work is part...

La Ciudad de Managua ha sido afectada en varias ocasiones por terremotos que le han ocasionado grandiosas pérdidas económicas y de vidas humanas. Como capital de Nicaragua, es el principal centro urbano, político y económico de la nación. Esta combinación de alta amenaza sísmica, concentración de bienes y de población, hacen de ella la ciudad con m...

Grandes terremotos en el océano pacífico y mar caribe de América Central, han generado más de cincuenta tsunamis que han afectado las costas del Pacífico y del Caribe en América Central en los últimos 500 años. El tsunami más destructivo fue el de Nicaragua en 1992 que generó olas de hasta 10 metros de altura. Ante la necesidad de salvaguardar la v...

We elaborated a tsunami risk map for Puerto Armuelle located in the Gulf of Chiriquí, Western Panama. The town is endangered mainly by local tsunamis caused by large earthquakes 1) in the Gulf of Chiriquí and the Pacific coast of Southwestern Panama; 2) near the Pacific Ocean of Southern Costa Rica and 3) near the Pacific coast of Colombia and Ecua...

Momotombo volcano, Nicaragua, erupted on December 1, 2015, after 110 years of inactivity. We present the results of the seismic monitoring of the volcano before and during the eruption. The eruption was preceded by a seismic swarm and seismic tremor several days and hours before the beginning of the activity. Seismic tremor increased drastically wh...

A partir del 15 de abril 2015, se comenzó a observar un aumento del número de sismos de tipo LP que duró hasta el mes de junio, con frecuencias bajas de 0.9Hz. La amplitud sísmica (RSAM) se mantuvo casi constante en 14 unidades, durante esta actividad. En noviembre se inicia una fase de sismos de tipo VT con magnitudes menores a 3.5, con profundida...

Nicaragua, like much of Central America, suffers from frequent damaging earthquakes (6 M7+ earthquakes occurred in the last 100 years). Thrust events occur at the Middle America Trench where the Cocos plate subducts by 72-81 mm/yr eastward beneath the Caribbean plate. Shallow crustal events occur on-shore, with potential extensive damage as demonst...

Desde agosto de 2015, se desarrolla un enjambre sísmico en el municipio de El Sauce, Nicaragua con magnitudes de los sismos hasta 4.9 Richter (el enjambre no ha cesado hasta la fecha de realizar esta presentación). Por el posible incremento de las lluvias que se esperaba para los meses septiembre a noviembre (normalmente los meses de mayores precip...

Central American landslides have caused great economic damage and loss of life. These problems may be alleviated by a rapid response enabled by accurate decision support systems. A daily nowcast model called Landslide Hazard Assessment for Situational Awareness (LHASA) was developed to meet this need. LHASA combines a regional landslide susceptibil...

Con el fin de mantener un mejor control acerca de los deslizamientos en Nicaragua, se ha venido desarrollando una base de datos desde el año 2004, sobre los parámetros geológicos, meteorológicos y geométricos y eventuales daños causados de aquellos deslizamientos, lahares y derrumbes en diferentes partes del país que suelen a repetirse siempre en e...

El Ayote, ubicada en la Región Autónoma del Caribe Sur (RACS). Fue uno de los municipios afectados por deslizamientos causados causadas por lluvias extremas el 23 de Junio de 2014. Las comunidades de Cerro Azul, La Gongolona y Pilan, se vieron afectadas por más de 380 procesos de inestabilidad de laderas entre ellos, flujos de detritos, flujos de l...

En 2010, como consecuencia, de un proyecto de investigación (referencia del proyecto) que lidera el grupo de Volcanismo Activo del Consejo Superior de Investigaciones Científicas (CSIC) se establece una colaboración entre el CSIC, el INETER (Nicaragua) y el Laboratorio de Astronomía, Geodesia y Cartografía de la Universidad de Cádiz (LAGC). Entre l...

Anomalous changes in the diffuse emission of carbon dioxide within the Masaya caldera have been observed before two seismic events that occurred at 10 and 30 km from the observation site. Their epicenters are located, respectively, south of Managua in Las Colinas (4.3 magnitude) and the Xiloa caldera (3.6 magnitude), in 2002 and 2003, recorded by t...

Anomalous changes in the diffuse emission of carbon dioxide within the Masaya caldera have been observed before two seismic events that occurred at 10 and 30 km from the observation site. Their epicenters are located, respectively, south of Managua in Las Colinas (4.3 magnitude) and the Xiloa caldera (3.6 magnitude), in 2002 and 2003, recorded by t...

We use measurements at 35 GPS stations in northern Central America and 25 seismometers at teleseismic distances to estimate the distribution of slip, source time function and Coulomb stress changes of the Mw = 7.3 2009 May 28, Swan Islands fault earthquake. This event, the largest in the region for several decades, ruptured the offshore continuatio...

We performed a reconnaissance about Early Warning Systems (EWS) on Landslides (EWSL) in the countries of Central America. The advance of the EWSL began in the 1990-ies and accelerated dramatically after the regional disaster provoked by Hurricane Mitch in 1998. In the last decade, Early Warning Systems were intensely promoted by national and intern...

The Tiscapa maar in the center of Managua city formed by a phreatomagmatic eruption <3ka ago. The eruption excavated a crater deep into the basement exposing a coherent Pleistocene to Holocene volcaniclastic succession that we have divided into four formations. The lowermost, >60ka old basaltic–andesitic formation F1 comprises mafic ignimbrites and...

SKS and SKKS splitting observations are used to constrain the pattern of mantle flow in the Central American subduction zone beneath Costa Rica and Nicaragua. After removing the effects of shallow wedge anisotropy on SK(K)S waveforms, a best fitting model of anisotropy beneath the Cocos Plate and in the deeper mantle wedge is determined. Fast polar...

Quiescently active volcanoes, which exhibit high background levels of geophysical activity, do not have clearly distinct ’background’ and ’unrest’ states and as such present a challenge for detecting changes in volcanic behaviour. Sustained unrest at quiescently active volcanoes may be driven by sluggish convection in a shallow magma chamber. This...

In the Nicaraguan segment of the Central American subduction zone, bookshelf faulting has been proposed as the dominant style of Caribbean plate deformation in response to oblique subduction of the Cocos plate. A key element of this model is left-lateral motion on arc-normal strike-slip faults. On 3 August 2005, a Mw 6.3 earthquake and its extensiv...

Cerro Negro volcano is the youngest of a group of cinder cones NW of Las Pilas at 25 km from León (Nicaragua) with 685 meters above sea level and one of the most active volcanoes of Nicaragua. It has erupted 21 times since its birth in 1850, with an eruptive cycle about 7-8 years. Since the last eruption, occurred on 5 August 1999, with erupted lav...

Seismic Hazard, Volcanic Hazard, seismic monitoring, proposal for the improvement of the seismic network

We present the stratigraphy, lithology, volcanology, and age of the Acahualinca section in Managua, including a famous footprint layer exposed in two museum pits. The ca. 4-m-high walls of the main northern pit (Pit I) expose excellent cross sections of Late Holocene volcaniclastic deposits in northern Managua. We have subdivided the section into s...

We present new shear wave splitting data from local events in Costa Rica and Nicaragua recorded by the temporary (July 2004 to March 2006) 48-station TUCAN broadband seismic array. Observed fast polarization directions in the fore arc, arc, and back arc range from arc-parallel to arc-normal over very short distances (<5 km when plotted at raypath m...

We present the first regional surface velocity field for Central America, showing crustal response to interaction of the Cocos and Caribbean plates. Elastic half-space models for interseismic strain accumulation on the dipping subduction plate boundary fit the GPS data well and show strain accumulation offshore and beneath the Nicoya and Osa penins...

Fast floods, currents and lahars caused by strong and/or long lasting rains represent mayor hazards at Central American volcanoes. An extreme example was the event at Casita volcano, Nicaragua, where around 2000 people were killed during Hurricane Mitch in 1998. Year by year, smaller events occur in the flanks of the volcanoes affecting population...

A successful landslide hazard and risk assessment requires awareness and good understanding of the potential landslide problems within the geographic area involved. However, this requirement is not always met in developing countries where population, scientific community, and the government may not be aware of the landslide threat. The landslide ha...

In September 2007, the Hurricane Felix devastated the North-eastern of Nicaragua, near the Caribbean coast. The hurricane heavily affected about 400 communities from a total of 777 registered in this region. As part of the post-disaster relief measures, INETER (The National Geosciences Institute) in collaboration with other Nicaraguan agencies was...

Understanding the pattern of solid mantle deformation in subduction zones is fundamentally important in constraining its effect on geodynamic processes such as material transport and thermal structure. Measurements of shear-wave splitting, and perhaps even travel-time anomalies, in both local and teleseismic (e.g., S,SKS,PKS) body waves allow us to...

The goal of this study is to image crust and mantle structure in the Nicaragua-Costa Rica subduction zone by applying Rayleigh wave tomography to waveforms recorded by the TUCAN Broadband Seismometer Experiment. The 48-station TUCAN array included two dense station lines normal to the arc, one in Nicaragua and the other in Costa Rica, and two spars...

Over the past decade, remote sensing has been used increasingly in the study of active volcanoes and their associated hazards. Ground‐based remote sensing techniques, such as those aimed at the analysis of volcanic gases or fumarole temperatures, are now part of routine monitoring operations with additional satellite‐based remote sensing methods. I...

Attenuation structure in the Central American subduction zone was imaged using local events recorded by the Tomography Under Costa Rica and Nicaragua array, a 20-month-long deployment (July 2004 until March 2006) of 48 seismometers that spanned the fore-arc, arc, and back-arc regions of Nicaragua and Costa Rica. P and S waveforms were inverted sepa...

Subduction alters continents several ways, including accretion, magmatic addition, mantle wedge serpentinization, and crustal differentiation. These changes affect seismic velocities, so characterizing upper plate crust establishes a baseline for composition and continental growth. Teleseismic P and PP arrivals from a temporary deployment of broadb...

The Central American subduction zone exhibits large variations in geochemistry, downgoing plate roughness and dip, and volcano locations over a short distance along the arc. Results from joint inversions for Vp, Vp/Vs, and hypocenters from the Tomography Under Costa Rica and Nicaragua (TUCAN) experiment give insight into its geometry and structure....

Resolving flow geometry in the mantle wedge is central to understanding the thermal and chemical structure of subduction zones, subducting plate dehydration, and melting that leads to arc volcanism, which can threaten large populations and alter climate through gas and particle emission. Here we show that isotope geochemistry and seismic velocity a...

Resolving flow geometry in the mantle wedge is central to understanding the thermal and chemical structure of subduction zones, subducting plate dehydration, and melting that leads to arc volcanism, which can threaten large populations and alter climate through gas and particle emission. Here we show that isotope geochemistry and seismic velocity a...

Subduction zone processes alter the upper plate in a number of ways, including accretion, magmatic addition, serpentinization of the mantle wedge and formation of mafic cumulates in the lower crust. All of these changes affect seismic velocities, and characterizing the structure of underlying terranes in Central America establishes a baseline for c...

Sulphur dioxide (SO2) and halogen oxide emissions were measured at Masaya Volcano in Nicaragua in April 2007 using differential optical absorption spectroscopy (DOAS). Next to passive DOAS measurements using scattered sunlight, an active long-path DOAS system was operated for several days with the light beam crossing the crater of the volcano. Thes...

The NOVAC project, funded by European Union, was started in October 2005 with the aim to establish a global network of stations for the quantitative measurement of volcanic gas emissions. The network is based on a novel type of instrument, the Scanning Dual-beam mini-DOAS. Primarily the instruments will be used to provide new parameters in the tool...

El proyecto mundial NOVAC (2005 – 2009) financiado por el sexto programa marco de la Comisión de la Unión Europea, consiste en establecer una red global de estaciones para la medición cuantitativa de las emisiones de los gases volcánicos por espectroscopía de absorción ultravioleta, haciendo uso de un nuevo tipo de instrumento – el mini-DOAS desarr...

A digital landslide database has been created for Nicaragua to provide the scientific community and national authorities with a tool for landslide-hazard assessment, emergency management, land-use planning, development of early warning systems, and the implementation of public and private policies. The Instituto Nicaragüense de Estudios Territorial...

A flooding hazard study was realized 2004-2006 through technical cooperation of Japan International Cooperation Agency (JICA) with INETER, upon the request of the Government of Nicaragua. The resulting hazard map shows the inundated area for a 200 years return period flood in a small riverbasin (65 square kilometers) near the Nicaraguan Pacific Coa...