Vlad Manea | Universidad Nacional Autónoma de México (original) (raw)

Papers by Vlad Manea

9th Congress of the Balkan Geophysical Society, 2017

To avoid shortcomings of the current models attempting to explain genesis of the Vrancea intermed... more To avoid shortcomings of the current models attempting to explain genesis of the Vrancea intermediate-depth earthquakes the alternative model of an unstable triple junction (VTJ) had been previously proposed mainly based on a speculative approach. The paper deals with results of the latest research, including high-resolution seismic tomography obtained through the joint inversion of seismic and gravity data, and numerical modelling of the mantle convection that brings new evidence to support VTJ as a valid alternative for Vrancea intermediate-depth seismicity geodynamic setting. Of a special interest proved to be the advanced numerical modelling run on a High Performance Computing Cluster own by Solid Earth Dynamics Department in the Institute of Geodynamics of the Romanian Academy that has demonstrated how a stable triple lithospheric contact may transform into an unstable triple junction under the influence of a thermal anomaly even in the absence of differences between the plates velocities.

Acta Universitaria, 2012

Presently, the Solid Earth Sciences started to move towards implementing High Performance Computa... more Presently, the Solid Earth Sciences started to move towards implementing High Performance Computational (HPC) research facilities. One of the key tenants of HPC is performance, which strongly depends on the interaction between software and hardware. In this paper, they are presented benchmark results from two HPC systems. Testing a Computational Fluid Dynamics (CFD) code specific for Solid Earth Sciences, the HPC system Horus, based on Gigabit Ethernet, performed reasonably well compared with its counterpart CyberDyn, based on Infiniband QDR fabric. However, the HPCC CyberDyn based on low-latency high-speed QDR network dedicated to MPI traffic outperformed the HPCC Horus. Due to the high-resolution simulations involved in geodynamic research studies, HPC facilities used in Earth Sciences should benefit from larger up-front investment in future systems that are based on high-speed interconnects.

J Volcanol Geotherm Res, 2008

Geophysical Monograph Series, 2007

Geografiska Annaler: Series A, Physical Geography, 2010

ABSTRACT. Lahars are hazardous events that can cause serious damage to people who live close to v... more ABSTRACT. Lahars are hazardous events that can cause serious damage to people who live close to volcanic areas; several were registered at different times in the last century, such as at Mt St Helens (USA) in 1980, Nevado del Ruiz (Colombia) in 1985 and Mt Pinatubo (Philippines) in 1990. Risk maps are currently used by decision-makers to help them plan to mitigate the hazard-risk of lahars. Risk maps are acquired based on a series of tenets that take into account the distribution and chronology of past lahar deposits, and ...

A GPS (Global Positioning System) network has been established in the Mexican state of Oaxaca wit... more A GPS (Global Positioning System) network has been established in the Mexican state of Oaxaca with the aim to understand the subduction-related seismotectonic regime in the area. Permanent GPS stations have been operating since 2000. Data from campaign GPS sites have been acquired every year for the period between 2001 and 2004. The observed average displacements corresponding to the epochs of 2001-2002 and 2002-2003 differ significantly from the crustal displacements for the apparent interslip steady ...

A finite element method is applied to model the thermal structure of the subducted Pacific plate ... more A finite element method is applied to model the thermal structure of the subducted Pacific plate and overlying mantle wedge beneath the southern part of the Kamchatka peninsula. A numerical scheme solves a system of 2D Navier-Stokes equations and a 2D steady state heat transfer equation. A model with isoviscous mantle exposed very low temperatures (~ 800ºC) in the mantle wedge, which cannot account for magma generation below the volcanic belt. Instead, a model with strong temperature-dependent ...

AGU Fall Meeting Abstracts, Dec 1, 2008

The relative contributions of lithosphere vs. upwelling sub-lithospheric mantle to formation of S... more The relative contributions of lithosphere vs. upwelling sub-lithospheric mantle to formation of Snake River Plain-Yellowstone (SRPY) basaltic magmas remains an ongoing debate. The association of this province with initially thick and cold Archean lithosphere (Wyoming craton) poses a problem in that this lid will probably hinder and possibly prevent melting of rising plume hot material. However, petrologic modeling indicates that SRPY primitive basalts last segregated from mantle at~ 1450 C and~ 100 km depth, suggesting ...

AGU Fall Meeting Abstracts, Dec 1, 2009

The Volcán de Colima (CV) is currently the most active Mexican volcano. After the 1913 plinian ac... more The Volcán de Colima (CV) is currently the most active Mexican volcano. After the 1913 plinian activity the volcano presented several eruptive phases that lasted few years, but since 1991 its activity became more persistent with vulcanian eruptions, lava and dome extrusions. During the last 15 years the volcano suffered several eruptive episodes as in 1991, 1994, 1998-1999, 2001-2003, 2004 and 2005 with the emplacement of pyroclastic flows. During rain seasons lahars are frequent affecting several infrastructures such as ...

… 2010, held 2-7 May, 2010 in …, May 1, 2010

Today, we are provided with an abundance of visual images from a variety of sources. In doing res... more Today, we are provided with an abundance of visual images from a variety of sources. In doing research, data visualization represents an important part, and sophisticated models require special tools that should enhance the comprehension of modeling results. Also, helping our students gain visualization skills is an important way to foster greater comprehension when studying geosciences. For these reasons we build a 3D stereo-visualization system, or a GeoWall, that permits to explore in depth 3D modeling ...

Flat slab subduction occurs at~ 10% of the active convergent margins and it is assumed that subdu... more Flat slab subduction occurs at~ 10% of the active convergent margins and it is assumed that subduction of oceanic aseismic ridges or seamount chains is the main mechanism to produce very low angle subduction slabs. However, recent numeric and analog modeling showed that ridges alone of moderate dimensions subducted perpendicular to the trench are not sufficient to produce flat-slab geometries. Therefore an alternative mechanism able to produce flat-slabs is required. In this paper we present ...

… 2010, held 2-7 May, 2010 in …, May 1, 2010

Today's scientists need access to new information technology capabilities, able to perform h... more Today's scientists need access to new information technology capabilities, able to perform high-resolution complex computing simulations in a reasonable time frame. Sophisticated simulation tools allow us to study phenomena that can never be observed or replicated by standard laboratory experiments. Modeling complex natural processes in general, and numerical computation in particular, represents today an essential need of research, and all modern research centers benefit from a computing center of one form or ...

… 2010, held 2-7 May, 2010 in …, May 1, 2010

Forearcs located above active subduction zones are generally characterized by low heat flow value... more Forearcs located above active subduction zones are generally characterized by low heat flow values, and this is considered a consequence of the subduction of cold slabs beneath continental plates. In the case of Central Mexico, the geometry of the subducting Cocos plate is quite unusual, the slab runs flat for several hundreds of kilometers before plunging into the asthenosphere. This particular geometry has a strong influence on the temperature distribution of the overriding plate where very low heatflow values are ...

… 2010, held 2-7 May …, May 1, 2010

The Volcán de Colima (CV) is currently the most active Mexican volcano. After the 1913 plinian ac... more The Volcán de Colima (CV) is currently the most active Mexican volcano. After the 1913 plinian activity the volcano presented several eruptive phases that lasted few years, but since 1991 its activity became more persistent with vulcanian eruptions, lava and dome extrusions. During the last 15 years the volcano suffered several eruptive episodes as in 1991, 1994, 1998-1999, 2001-2003, 2004 and 2005 with the emplacement of pyroclastic flows. During rain seasons lahars are frequent affecting several infrastructures such as ...

Volcanic rocks located in the central segment of the Eastern Volcanic Belt of Kamchatka show a hi... more Volcanic rocks located in the central segment of the Eastern Volcanic Belt of Kamchatka show a high variability, both in age as well as in the geochemical composition. Three principal groups have been identified, an older group (7-12 my) represented by rich alkaline and transitional basalts, a 7-8 my group exemplified by alkaline basalts of extreme plume type, and a younger group (3-8 my) characterized by calc-alkaline andesites and dacites rocks. Moreover, the younger group shows an adakitic signature. The magmas are ...

Presently, the solid earth sciences started to move towards implementing high performance computa... more Presently, the solid earth sciences started to move towards implementing high performance computational (HPC) research facilities. One of the key tenants of HPC is performance, and designing a HPC solution tailored to a specific research field as solid earth that represents an optimum price/performance ratio is often a challenge. The HPC system performance strongly depends on the software-hardware interaction, and therefore prior knowledge on how well specific parallelized software performs on different HPC ...

Plates, Plumes, and Paradigms, 2005

A finite element method is applied to model the thermal structure of the subducted Pacific plate ... more A finite element method is applied to model the thermal structure of the subducted Pacific plate and overlying mantle wedge beneath the southern part of the Kamchatka peninsula. A numerical scheme solves a system of 2D Navier-Stokes equations and a 2D steady state heat transfer equation. A model with the izoviscous mantle exposed very low temperatures (~ 800 ºC) in the mantle wedge, which cannot account for the magma generation below the volcanic belt. Instead, a model with the strong temperature ...

Nature Communications, 2014

Acta Universitaria, 2012

The problem of convective flows in a highly viscous fluid represents a common research direction ... more The problem of convective flows in a highly viscous fluid represents a common research direction in Earth sciences. For tracing the convective motion of the fluid material, a source passive particles (or tracers) that flow at a local convection velocity and do not affect the pattern of flow it is commonly used. Here we present a parallelized tracer code that uses passive and weightless particles with their position computed from their displacement during a small time interval at the velocity of flow previously calculated for a given point in space and time. The tracer code is integrated in the open source package CitcomS, which is widely used in the solid earth community (www.geodynamics.org). We benchmarked the tracer code on the state-of-the-art CyberDyn parallel machine, a High Performance Computing (HPC) Cluster with 1344 computing cores available at the Institute of Geodynamics of the Romanian Academy.

9th Congress of the Balkan Geophysical Society, 2017

To avoid shortcomings of the current models attempting to explain genesis of the Vrancea intermed... more To avoid shortcomings of the current models attempting to explain genesis of the Vrancea intermediate-depth earthquakes the alternative model of an unstable triple junction (VTJ) had been previously proposed mainly based on a speculative approach. The paper deals with results of the latest research, including high-resolution seismic tomography obtained through the joint inversion of seismic and gravity data, and numerical modelling of the mantle convection that brings new evidence to support VTJ as a valid alternative for Vrancea intermediate-depth seismicity geodynamic setting. Of a special interest proved to be the advanced numerical modelling run on a High Performance Computing Cluster own by Solid Earth Dynamics Department in the Institute of Geodynamics of the Romanian Academy that has demonstrated how a stable triple lithospheric contact may transform into an unstable triple junction under the influence of a thermal anomaly even in the absence of differences between the plates velocities.

Acta Universitaria, 2012

Presently, the Solid Earth Sciences started to move towards implementing High Performance Computa... more Presently, the Solid Earth Sciences started to move towards implementing High Performance Computational (HPC) research facilities. One of the key tenants of HPC is performance, which strongly depends on the interaction between software and hardware. In this paper, they are presented benchmark results from two HPC systems. Testing a Computational Fluid Dynamics (CFD) code specific for Solid Earth Sciences, the HPC system Horus, based on Gigabit Ethernet, performed reasonably well compared with its counterpart CyberDyn, based on Infiniband QDR fabric. However, the HPCC CyberDyn based on low-latency high-speed QDR network dedicated to MPI traffic outperformed the HPCC Horus. Due to the high-resolution simulations involved in geodynamic research studies, HPC facilities used in Earth Sciences should benefit from larger up-front investment in future systems that are based on high-speed interconnects.

J Volcanol Geotherm Res, 2008

Geophysical Monograph Series, 2007

Geografiska Annaler: Series A, Physical Geography, 2010

ABSTRACT. Lahars are hazardous events that can cause serious damage to people who live close to v... more ABSTRACT. Lahars are hazardous events that can cause serious damage to people who live close to volcanic areas; several were registered at different times in the last century, such as at Mt St Helens (USA) in 1980, Nevado del Ruiz (Colombia) in 1985 and Mt Pinatubo (Philippines) in 1990. Risk maps are currently used by decision-makers to help them plan to mitigate the hazard-risk of lahars. Risk maps are acquired based on a series of tenets that take into account the distribution and chronology of past lahar deposits, and ...

A GPS (Global Positioning System) network has been established in the Mexican state of Oaxaca wit... more A GPS (Global Positioning System) network has been established in the Mexican state of Oaxaca with the aim to understand the subduction-related seismotectonic regime in the area. Permanent GPS stations have been operating since 2000. Data from campaign GPS sites have been acquired every year for the period between 2001 and 2004. The observed average displacements corresponding to the epochs of 2001-2002 and 2002-2003 differ significantly from the crustal displacements for the apparent interslip steady ...

A finite element method is applied to model the thermal structure of the subducted Pacific plate ... more A finite element method is applied to model the thermal structure of the subducted Pacific plate and overlying mantle wedge beneath the southern part of the Kamchatka peninsula. A numerical scheme solves a system of 2D Navier-Stokes equations and a 2D steady state heat transfer equation. A model with isoviscous mantle exposed very low temperatures (~ 800ºC) in the mantle wedge, which cannot account for magma generation below the volcanic belt. Instead, a model with strong temperature-dependent ...

AGU Fall Meeting Abstracts, Dec 1, 2008

The relative contributions of lithosphere vs. upwelling sub-lithospheric mantle to formation of S... more The relative contributions of lithosphere vs. upwelling sub-lithospheric mantle to formation of Snake River Plain-Yellowstone (SRPY) basaltic magmas remains an ongoing debate. The association of this province with initially thick and cold Archean lithosphere (Wyoming craton) poses a problem in that this lid will probably hinder and possibly prevent melting of rising plume hot material. However, petrologic modeling indicates that SRPY primitive basalts last segregated from mantle at~ 1450 C and~ 100 km depth, suggesting ...

AGU Fall Meeting Abstracts, Dec 1, 2009

The Volcán de Colima (CV) is currently the most active Mexican volcano. After the 1913 plinian ac... more The Volcán de Colima (CV) is currently the most active Mexican volcano. After the 1913 plinian activity the volcano presented several eruptive phases that lasted few years, but since 1991 its activity became more persistent with vulcanian eruptions, lava and dome extrusions. During the last 15 years the volcano suffered several eruptive episodes as in 1991, 1994, 1998-1999, 2001-2003, 2004 and 2005 with the emplacement of pyroclastic flows. During rain seasons lahars are frequent affecting several infrastructures such as ...

… 2010, held 2-7 May, 2010 in …, May 1, 2010

Today, we are provided with an abundance of visual images from a variety of sources. In doing res... more Today, we are provided with an abundance of visual images from a variety of sources. In doing research, data visualization represents an important part, and sophisticated models require special tools that should enhance the comprehension of modeling results. Also, helping our students gain visualization skills is an important way to foster greater comprehension when studying geosciences. For these reasons we build a 3D stereo-visualization system, or a GeoWall, that permits to explore in depth 3D modeling ...

Flat slab subduction occurs at~ 10% of the active convergent margins and it is assumed that subdu... more Flat slab subduction occurs at~ 10% of the active convergent margins and it is assumed that subduction of oceanic aseismic ridges or seamount chains is the main mechanism to produce very low angle subduction slabs. However, recent numeric and analog modeling showed that ridges alone of moderate dimensions subducted perpendicular to the trench are not sufficient to produce flat-slab geometries. Therefore an alternative mechanism able to produce flat-slabs is required. In this paper we present ...

… 2010, held 2-7 May, 2010 in …, May 1, 2010

Today's scientists need access to new information technology capabilities, able to perform h... more Today's scientists need access to new information technology capabilities, able to perform high-resolution complex computing simulations in a reasonable time frame. Sophisticated simulation tools allow us to study phenomena that can never be observed or replicated by standard laboratory experiments. Modeling complex natural processes in general, and numerical computation in particular, represents today an essential need of research, and all modern research centers benefit from a computing center of one form or ...

… 2010, held 2-7 May, 2010 in …, May 1, 2010

Forearcs located above active subduction zones are generally characterized by low heat flow value... more Forearcs located above active subduction zones are generally characterized by low heat flow values, and this is considered a consequence of the subduction of cold slabs beneath continental plates. In the case of Central Mexico, the geometry of the subducting Cocos plate is quite unusual, the slab runs flat for several hundreds of kilometers before plunging into the asthenosphere. This particular geometry has a strong influence on the temperature distribution of the overriding plate where very low heatflow values are ...

… 2010, held 2-7 May …, May 1, 2010

The Volcán de Colima (CV) is currently the most active Mexican volcano. After the 1913 plinian ac... more The Volcán de Colima (CV) is currently the most active Mexican volcano. After the 1913 plinian activity the volcano presented several eruptive phases that lasted few years, but since 1991 its activity became more persistent with vulcanian eruptions, lava and dome extrusions. During the last 15 years the volcano suffered several eruptive episodes as in 1991, 1994, 1998-1999, 2001-2003, 2004 and 2005 with the emplacement of pyroclastic flows. During rain seasons lahars are frequent affecting several infrastructures such as ...

Volcanic rocks located in the central segment of the Eastern Volcanic Belt of Kamchatka show a hi... more Volcanic rocks located in the central segment of the Eastern Volcanic Belt of Kamchatka show a high variability, both in age as well as in the geochemical composition. Three principal groups have been identified, an older group (7-12 my) represented by rich alkaline and transitional basalts, a 7-8 my group exemplified by alkaline basalts of extreme plume type, and a younger group (3-8 my) characterized by calc-alkaline andesites and dacites rocks. Moreover, the younger group shows an adakitic signature. The magmas are ...

Presently, the solid earth sciences started to move towards implementing high performance computa... more Presently, the solid earth sciences started to move towards implementing high performance computational (HPC) research facilities. One of the key tenants of HPC is performance, and designing a HPC solution tailored to a specific research field as solid earth that represents an optimum price/performance ratio is often a challenge. The HPC system performance strongly depends on the software-hardware interaction, and therefore prior knowledge on how well specific parallelized software performs on different HPC ...

Plates, Plumes, and Paradigms, 2005

A finite element method is applied to model the thermal structure of the subducted Pacific plate ... more A finite element method is applied to model the thermal structure of the subducted Pacific plate and overlying mantle wedge beneath the southern part of the Kamchatka peninsula. A numerical scheme solves a system of 2D Navier-Stokes equations and a 2D steady state heat transfer equation. A model with the izoviscous mantle exposed very low temperatures (~ 800 ºC) in the mantle wedge, which cannot account for the magma generation below the volcanic belt. Instead, a model with the strong temperature ...

Nature Communications, 2014

Acta Universitaria, 2012

The problem of convective flows in a highly viscous fluid represents a common research direction ... more The problem of convective flows in a highly viscous fluid represents a common research direction in Earth sciences. For tracing the convective motion of the fluid material, a source passive particles (or tracers) that flow at a local convection velocity and do not affect the pattern of flow it is commonly used. Here we present a parallelized tracer code that uses passive and weightless particles with their position computed from their displacement during a small time interval at the velocity of flow previously calculated for a given point in space and time. The tracer code is integrated in the open source package CitcomS, which is widely used in the solid earth community (www.geodynamics.org). We benchmarked the tracer code on the state-of-the-art CyberDyn parallel machine, a High Performance Computing (HPC) Cluster with 1344 computing cores available at the Institute of Geodynamics of the Romanian Academy.

Pentru forma finala a acestui material , adoptat ca de catre Consiliul National de Etica (CNE) dr... more Pentru forma finala a acestui material , adoptat ca de catre Consiliul National de Etica (CNE) drept Ghid pentru identificarea plagiatului, la sfarsitul anului 2017, vezi siteul institutiei la http://cne.ancs.ro/wp-content/uploads/cne/2017/12/Ghid_identificare_plagiat_final_site.pdf (completare 15 ianuarie 2018).

Materialul prezintă principii și bune practici în diagnosticarea plagiatului. Poate fi un instrument util în diagnoza cazurilor de nerespectare a deontologiei de cercetare științifică. Este destinat, în principal, activității de la nivelul Consiliului Național de Etică (CNE) dar poate fi folosit ca ghid și în alte situații similare din spațiile academic-universitare. Elaborat de membri ai CNE : Dumitru Sandu, Dacian Dragos , Diaconescu Dragos ,Silvia Florea , Vlad Manea,Denisa Margina, Lucian Nastasa Kovacs, Adrian Nita ,Popa Marcel ,Ioana Popescu, Maria Radone , Liliana Rusu , Carmen-Adella Sirbu, Eugen Stamate . Februarie 2017