GeoCoffee

Terratrèmol Granada/Jaén

2012-02-01T11:34:00.004+01:00

No es veu massa bé doncs a aquesta hora encara hi ha gent que trafega, però aqui va el registre del terratrèmol obtingut a una estació que tenim al soterrani de l'ICTJA per a fer-hi proves.

Terremoto Granada

2012-01-31T20:53:00.003+01:00

¿Es normal esta discrepancia en la localización entre IGN y USGS?
Son 23 km de diferencia!

http://earthquake.usgs.gov/earthquakes/recenteqsww/Quakes/us2012wkam.php#scitech

http://www.ign.es/ign/layoutIn/sismoPrincipalTensorUltimo.do?evid=1124344

Tambe registrem terratremols

2012-01-30T11:00:00.002+01:00

A part de gent celebrant gols, el sismometre de l'entrada tambe enregistra terratremols, com aquest al Nord d'Italia del passat divendres

Ma & Myr again

2012-01-29T20:44:00.006+01:00

En aquest article un famós científic comenta de nou el tema dels Ma (million years ago) i Myr (million years period)....

Christie-blick, N., 2012. Conventions and Symbols. GSA Today 2010-2011.

Gols del Barça

2012-01-26T17:36:00.002+01:00

Registre dels gols del Barça d'ahir en un sismometre instalat al sotan del institut. Entre els dos gols, el registre de l'esclat de coets (crec...)

Jordi

Resolucio Google Earth

2012-01-25T19:09:00.003+01:00

Comparació entre una foto aerea i una captura de pantalla de Google Earth. La resolucio dels DEM utilitzats no està del tot malament.... Per cert, suposo que tots sabreu d'on es tracta

Jordi

Inicio de los seminarios de Estructura y Dinámica de la Tierra

2012-01-17T14:11:00.002+01:00

Con esta charla comienzan los seminarios de la línea de investigación Estructura y Dinámica de la Tierra del ICTJA. La idea es hacer uno de estos seminarios cada dos semanas aproximadamente, con el fin de que los estudiantes de doctorado presenten los trabajos que están realizando como parte de su tesis. Esto no excluye que cualquiera (investigador, visita, etc) que tenga algo que quiera mostrar, pueda hacerlo a través de estas charlas.

Aquí está el anuncio del primer seminario:

Y ya tenemos el próximo reservado para Juan Alcalde.

Doodle

2012-01-11T18:17:00.001+01:00

Hola!

Otra chorrada. Pero supongo que todos habréis visto el doodle de hoy, dedicado a Nicolás Steno (o Niels Stensen). Os lo capturo aquí por si justo hoy no habéis abierto Google.

Megavolcán en Sumatra extinguirá la humanidad

2012-01-11T18:12:00.001+01:00

En fin... buscando información sobre el terremoto de ayer de Sumatra (7.3Mw, 29km depth según UGSC), me ha salido esta página sobre el fin del mundo del 21 de diciembre de 2012. Parece ser que ahora será por un megavolcán que, junto con la inversión polar simultánea en el sol y en la tierra, provocará el fin de la humanidad.

http://www.december212012.com/articles/disaster/Sumatra_earthquakes.htm

Propongo que aviséis a todos los organismos científicos conocidos, exigiendo financiación para la investigación de la Tierra, especialmente en geodinámica, o si no, el mundo se irá al garete...
Funcionará; más o menos es lo mismo que dicen los meteorólogos con el cambio global y ellos sí están ganando dinero ;D

(para que os distraigáis)

Saludos,

Juan-Luis

Mahdi Najafi: fellow at GDL

2011-12-30T13:51:00.003+01:00

I am Mahdi Najafi.
I am from Iran and I will stay at GDL for at least 6 months until early June 2012.
I work on my PhD thesis "Fold Style in Fars, Zagros Fold-Thrust Belt" in TMU (Tarbiat-Modares University in Tehran under the supervision of Prof. Ali Yassaghi
My office is in the corner with Eduard Saura and Emilio Casciello.
Jaume Vergés is my advisor.

Passive Seismic Monitoring of an Experimental CO2 Geological Storage Site in Hontomín (Northern Spain)

2011-12-24T12:00:00.001+01:00

Carbon dioxide capture and storage (CCS) has been recognized as a promising option for dealing with emissions from fossil fuel combustion to decrease the release of CO2 into the atmosphere. In this context, the Spanish Foundation “Ciudad de la Energía” (CIUDEN) is developing a CO2 Geological Storage Program in saline aquifers in Spain.

Distribution of the 30 seismic stations of the Hontomín Seismic Network (HO). Black triangles correspond to the 20 SS-45 sensors whereas the LE-3D seismometers are plotted with white triangles. The cross symbol marks the location of the possible CO2 injection point.

CO2 monitoring will play an essential role to control the possible leakage of the injected fluids to the atmosphere or other geologic formations and will help to track them in the subsurface over time. Passive seismic monitoring is a complementary technique that has potential as long-term, cost-effective method for continuous monitoring of CO2 injection activities. In this context, we have designed a passive seismic network consisting of 30 surface seismic stations and a borehole seismic array that has been deployed before the injection activities start. The Hontomín seismic network (code HO) is composed of 20 three-component SARA SS-45 sensors with natural frequency 4.5 Hz, and 10 Lennartz LE-3D seismometers with natural period 20 s, which have been deployed at about 2-meters in depth. The stations have been distributed, within logistical constraints, in concentric ellipses around the planned CO2 injection well. The interstation distances range from 1 to 2 km, thus covering an area of about 9 km x 8 km. Seismic data are acquired by means of SARA SL-06 digitizers at a sample rate of 200 Hz and they are continuously recorded on-site. The implementation of a digital radio link transmission to a recording data centre is in progress. The surface network will be supplemented in the near future with an array of 12 triaxial 8-12 Hz geophones in a well specifically designed for geophysical monitoring.

Images of station HO08. A detail of the instrumentation is also shown.

(a) Seismogram of a regional earthquake occurred in Lorca (southeastern Spain) at about 568 km from the site; (b) teleseismic recording of the Tohoku (Japan) earthquake occurred at a geodetic distance of about 10,410 km from Hontomín.

The analysis of the first available seismic data has allowed to estimate the ambient noise levels at the station sites and to validate the performance of the network to locate small magnitude induced earthquakes. The quantification of the station short-term noise baselines has served to characterize the seismic noise conditions at each site, as well as to provide us with a tool to assess the quality of the data. Further processing, such as the computation of earthquake locations, will rely on the quality of the seismic data acquired.

Three-component Power Spectral Density (PSD) for stations HO01 and HO27 (Lennartz 20 s seismometer, top) and stations HO20 and HO29 (SARA 4.5 Hz seismometer, bottom). The median and the 5% and 95% percentiles of the PSD distribution are plotted. The gray lines represent the New High Noise Model (NHNM) and New Low Noise Model (NLNM) of Peterson (1993)

Together with the identification of geomechanical deformations through the location of microseismic events, we plan to take advantage of the seismological technique Passive Image Interferometry (PII) to monitor small temporal changes of seismic velocities in the reservoir area. Preliminary correlation analyses performed with seismic noise data from HO network show that the source receiver co-located Green’s functions as well as for larger station distances can be computed for frequencies between 0.5 and 8 Hz with a temporal resolution of 1 day.

Temporal stability of the vertical component autocorrelation functions at station HO06 for the frequency range 0.5-1 Hz.

We can conclude that the CIUDEN Project at Hontomín test site constitutes a good opportunity to validate, under favorable conditions, the applicability of passive seismology techniques to monitor CO2 storage in deep saline formations.

Listen to a Paper - Messinian salinity crisis regulated by competing tectonics and erosion at the Gibraltar arc

2011-12-20T21:37:00.005+01:00

Browsing the web I found the following link:
http://www.nature.com/nature/podcast/
A mediterranean mysteryI think it is worth hearing it. The Nature Podcast from 15 December 2011.
Enjoy!

Ondulacions del sostre dels núvols al S de Paris

2011-12-07T14:24:00.005+01:00

Wave scattering d'alçada

2011-11-30T09:49:00.003+01:00

Bonic patró d'interferencia d'ones, amb la curiositat de que no es tracta de sismica sino de nuvols. L'imatge es una foto satelit del Mar del Nord (prop de les Faroe) i l'origen de les interferencies son les illes i illots que pertorben les corrents d'aire.
Mes informació a:
http://earthobservatory.nasa.gov/IOTD/view.php?id=76524&src=eoa-iotd

Ductile crustal flow in Europe's lithosphere

2011-11-29T11:33:00.001+01:00

Otro paper de la Tesauro y compañía sobre la litosfera Europea.
http://www.sciencedirect.com/science/article/pii/S0012821X11005759

En este trabajo usan sus modelos anteriores (de espesores cortical, litosférico, elástico, la resisténcia litosférica, ...) para determinar los gradientes laterales de presión resultantes de las variaciones de densidad y grosor cortical. Los gradientes de presión los utilizan para predecir las tasas de deformación del flujo dúctil. Comparando éste con la anisotropía del manto y las velocidades en superficie de GPS cuantifican el espesor de las zonas de baja viscosidad en la corteza inferior. En general, la corteza fluye alejándose de los orógenos hacia las zonas más débiles adyacentes.

Història profunda del Palau Sant Jordi

2011-11-29T09:25:00.006+01:00

Albert Ventayol Lázaro has sent you a message.

Date: 11/29/2011

Subject: Nueva entrada en GeoVentayol

Moviendo el Palau Sant Jordi. El subsuelo forzó un cambio en el emplazamiento original del Palau. http://www.geoventayol.blogspot.com/2011/11/moviendo-el-palau-sant-jordi.html

Proyecto Atlántropa

2011-11-28T11:52:00.000+01:00

Tan pronto como los geólogos de principios del siglo XX imaginaron el Mediterráneo desecado durante la era Mesiniense, un ingeniero alemán se obsesionó con llevarlo a la práctica. Herman Sörgel promocionó entre los acaudalados su enorme presa entre Algeciras y Tánger (el proyecto Atlantropa) con bastante éxito. Tenía el humanitario objetivo de impulsar el intercambio económico entre Europa y África, aprovechando la dudosa ventaja de un Mediterráneo parcialmente desecado. Poseído por su idea, no supo o no quiso ver los 'contras' de semejante disparate, pero la causa de su fracaso fue otra: los gobernantes de su país tenían por entonces planes menos filantrópicos para Europa y África, la Segunda Guerra Mundial llegó y Atlantropa (always look at the bright side) nunca llegó a la práctica.

Mapa del Proyecto Atlantropa (fuente: Wikimedia Commons)

Difícil de creer, pero todavía hay adeptos del proyecto, y de cierta reputación, así que cuidado porque a lo mejor nos lo secan, fijaos:

R.B. Cathcart, "What if We Lowered the Mediterranean Sea?", Speculations in Science and Technology, 8: 7-15 (1985).
R.B. Cathcart, "Mitigative Anthropogeomorphology: a revived 'plan' for the Mediterranean Sea Basin and the Sahara", Terra Nova: The European Journal of Geosciences, 7: 636-640 (1995).

Artículo interesante

2011-11-25T18:13:00.000+01:00

Mirad en este enlace:
http://www.agu.org/journals/gc/papersinpress.shtml#id2011GC003859

un artículo in press en G-cubed. Resulta que el segundo autor(a) hizo la promesa de correr una carrera de 10 km en un periodo de 3 meses a partir de la fecha de aceptación (15 de noviembre). Yo digo que si lo consigue (es culona, ma non troppo), que aporte a este blogg una prueba.

Esllavissament espectacular a California

2011-11-25T14:40:00.001+01:00

Podeu seguir la noticia i veure mes fotos a:

http://www.dailymail.co.uk/news/article-2064463/Scenic-throughway-muddy-abyss-Large-section-coastal-Los-Angeles-roadway-slides-ocean.html

Una mica de historia...

2011-11-25T12:21:00.000+01:00

Sobre marees i terratremols

Biografia de la Tierra

2011-11-25T12:17:00.000+01:00

El llibre de divulgació en Geologia d'en Paco Anguita ara disponible lliurament en pdf. Trobareu la noticia i el link per baixar el fitxer a:
http://geosfera-sgp.blogspot.com/2011/11/la-biografia-de-la-tierra-se-digitaliza.html?spref=tw

Paper con imagenes interesantes.

2011-11-25T11:18:00.000+01:00

Interpretation workflows enabled by a Domain Transform

Geoffrey A. Dorn* introduces the Domain Transform designed to substantially enhance imaging of depositional systems for rapid identification and interpretation. It also enables a number of new workflows intended to improve the efficiency and effectiveness of 3D seismic exploration and development.

http://fb.eage.org/content.php?section=7&issue=1804&lang=eng

Qué estaba haciendo antes..

2011-11-25T09:04:00.000+01:00

Vertical crustal motions from differential tide gauge observations and satellite altimetry in southern Italy

Carla Braitenberg, Patrizia Mariani, Lavinia Tunini, Barbara Grillo, Ildikò Nagy

Department of Geosciences, University Trieste, Via Weiss 1, 34100 Trieste, Italy

http://www.sciencedirect.com/science/article/pii/S0264370710001274

Our goal is to determine vertical crustal movement rates from tide gauge and satellite altimetry measurements. Tide gauges measure sea level, but as they are fixed to the crust, they sense both sea surface height variations and vertical crustal movements. The differential sea level rates of sufficiently nearby stations are a good means to determine differential crustal movement rates, when sea level height variations can be assumed to be homogeneous. Satellite altimetric measurements determine sea surface height variations directly and can be used to separate the crustal signal from the sea surface height variations in tide gauge measurements. The correction of the tide gauge sea level rates for the sea surface height contribution requires collocation of the satellite pass and the tide gauge station. We show that even if this is not the case, the satellite altimetric observations enable correction of differential tide gauge rates for the effects of sea surface rate inhomogeneities.
We apply the methodology to an area of broad scientific interest, due to its high seismic risk and its location as standpoint for a proposed major bridge connecting Sicily to the Italian mainland.
We find that the Southern Calabria and the eastern Sicily tide gauges have a deficit in sea level increase of 1–2 mm/yr with respect to the north western Sicilian tide gauge. The satellite altimetric observations show that this differential movement must be caused by a tectonic component, because the sea surface rates are higher offshore eastern Sicily compared to offshore western Sicily. The satellite altimetric rates show that the sea surface rates are inhomogeneous in the Mediterranean and have larger amplitudes as we move away from the coast than immediately offshore. Our technique can be applied to any part of the world where tide gauge observations are available, because satellite altimetric observations are global.

Annus o year

2011-11-24T13:16:00.001+01:00

Hola!

Me estreno con una tontería que ha provocado una acalorada discusión en el meeting group semanal aquí en Frankfurt.

Desde abril de 2011, la unidad múltiplo del segundo es annus, con símbolo "a". Queda desterrado el "y", el "yr", el "yrs" o todas las demás. Da igual si es "hacia atrás en el tiempo" (sugieren usar "ago" o "before present") o un intervalo aleatorio.

El geólogo de mi grupo está que trina.

La referencia está aquí. Tengo el paper, pero no se puede compartir vía blog. No obstante, seguro que podéis encontrarlo si os resulta curioso.

Pure Appl. Chem., Vol. 83, No. 5, pp. 1159–1162, 2011. doi:10.1351/PAC-REC-09-01-22

IUPAC-IUGS common definition and convention on the use of the year as a derived unit of time

Abstract: The units of time (both absolute time and duration) most practical to use when dealing with very long times, for example, in nuclear chemistry and earth and planetary sciences, are multiples of the year, or annus (a). Its proposed definition in terms of the SI base unit for time, the second (s), for the epoch 2000.0 is 1 a = 3.155 692 5445 × 107 s. Adoption of this definition, and abandonment of the use of distinct units for time differences, will bring the earth and planetary sciences into compliance with quantity calculus for SI and non-SI units of time.

Modelo de subducción

2011-11-24T12:40:00.000+01:00

Influence of lateral slab edge distance on plate velocity, trench velocity, and subduction partitioning

http://www.agu.org/journals/jb/jb1110/2011JB008535/

Abstract: Subduction of oceanic lithosphere occurs through both trenchward subducting plate motion and trench retreat. We investigate how subducting plate velocity, trench velocity and the partitioning of these two velocity components vary for individual subduction zone segments as a function of proximity to the closest lateral slab edge (D_SE). We present a global compilation for 207 trench segments from 17 active subduction zones on Earth and three-dimensional numerical models of progressive free subduction of a single oceanic plate that subducts into a stratified mantle. The results show that the subducting plate velocity is always high (≥5.1 cm/yr (models) and ≥4.2 cm/yr (nature)) and trench velocity is always low (≤2.5 cm/yr (models) and ≤1.7 cm/yr (nature)) in the center of wide subduction zones (D_SE > 2200 km). Only in regions close to lateral slab edges (D_SE < 1000 km), be it for narrow or wide subduction zones, can the trench velocity exceed 4 cm/yr (models) and 6 cm/yr (nature) and can the subducting plate velocity go below 4 cm/yr (models) and 2 cm/yr (nature). In general, plate velocities, trench velocities and subduction partitioning are much more variable near slab edges than in the center of wide subduction zones owing to other parameters that affect subduction kinematics. We conclude that subduction kinematics can vary considerably along individual subduction zones and that the upper bound values for trench velocity and lower bound values for subducting plate velocity and subduction partitioning at individual subduction zone segments depend critically onD_SE.