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Crustal structure of the northeastern margin of the Tibetan plateau from the Songpan-Ganzi terrane to the Ordos basin Crustal structure of the northeastern margin of the Tibetan plateau from the Songpan-Ganzi terrane to the Ordos basin

The 1000-km-long Darlag–Lanzhou–Jingbian seismic refraction profile is located in the NE margin of the Tibetan plateau. This profile crosses the northern Songpan-Ganzi terrane, the Qinling-Qilian fold system, the Haiyuan arcuate tectonic region, and the stable Ordos basin. The P-wave and S-wave velocity structure and Poisson's ratios reveal many significant characteristics in the profile...
Authors
M. Liu, Walter D. Mooney, S. Li, N. Okaya, Shane T. Detweiler

Airborne microorganisms in the African desert dust corridor over the mid-Atlantic ridge, Ocean Drilling Program, Leg 209 Airborne microorganisms in the African desert dust corridor over the mid-Atlantic ridge, Ocean Drilling Program, Leg 209

The objective of this study was to enhance our understanding of the fate and trans-Atlantic transport of dustborne microorganisms from Northern Africa to the Caribbean and Americas, and more specifically to determine if culturable populations could be detected at a mid-ocean site, closer to the source of dust relative to land-based Caribbean sites, during the early summer months of May...
Authors
Dale W. Griffin, Douglas L. Westphal, Michael A. Gray

Extreme U-Th disequilibrium in rift-related basalts, rhyolites and granophyric granite and the timescale of rhyolite generation, intrusion and crystallization at Alid volcanic center, Eritrea Extreme U-Th disequilibrium in rift-related basalts, rhyolites and granophyric granite and the timescale of rhyolite generation, intrusion and crystallization at Alid volcanic center, Eritrea

Rhyolite pumices and co-erupted granophyric (granite) xenoliths yield evidence for rapid magma generation and crystallization prior to their eruption at 15·2 ± 2·9 ka at the Alid volcanic center in the Danikil Depression, Eritrea. Whole-rock U and Th isotopic analyses show 230Th excesses up to 50% in basalts
Authors
J. B. Lowenstern, B. L. A. Charlier, M.A. Clynne, J. L. Wooden

Size distribution of submarine landslides and its implication to tsunami hazard in Puerto Rico Size distribution of submarine landslides and its implication to tsunami hazard in Puerto Rico

We have established for the first time a size frequency distribution for carbonate submarine slope failures. Using detailed bathymetry along the northern edge of the carbonate platform north of Puerto Rico, we show that the cumulative distribution of slope failure volumes follows a power-law distribution. The power-law exponent of this distribution is similar to those for rock falls on...
Authors
Uri S. ten Brink, E.L. Geist, B.D. Andrews

Statistical modeling of storm-level Kp occurrences Statistical modeling of storm-level Kp occurrences

We consider the statistical modeling of the occurrence in time of large Kp magnetic storms as a Poisson process, testing whether or not relatively rare, large Kp events can be considered to arise from a stochastic, sequential, and memoryless process. For a Poisson process, the wait times between successive events occur statistically with an exponential density function. Fitting an...
Authors
K.J. Remick, Jeffrey J. Love

Carbon dioxide emissions from vegetation-kill zones around the resurgent dome of Long Valley caldera, eastern California, USA Carbon dioxide emissions from vegetation-kill zones around the resurgent dome of Long Valley caldera, eastern California, USA

A survey of diffuse CO2 efflux, soil temperature and soil-gas chemistry over areas of localized vegetation-kill on and around the resurgent dome of Long Valley caldera California was performed to evaluate the premise that gaseous and thermal anomalies are related to renewed intrusion of magma. Some kill sites are long-lived features and others have developed in the past few years. Total...
Authors
Deborah Bergfeld, William C. Evans, James F. Howle, Christopher D. Farrar

Landslides triggered by the 2004 Niigata Ken Chuetsu, Japan, earthquake Landslides triggered by the 2004 Niigata Ken Chuetsu, Japan, earthquake

The Niigata Ken Chuetsu earthquake triggered a vast number of lanslides in the epicentral region. Landslide concentrations were among the highest ever measured after an earthquake, and most of the triggered landslides were relatively shallow failures parallel to the steep slope faces. The dense concentration of landslides can be attributed to steep local topography in relatively weak...
Authors
D.S. Kieffer, R. Jibson, E.M. Rathje, K. Kelson

Sustained long-period seismicity at Shishaldin Volcano, Alaska Sustained long-period seismicity at Shishaldin Volcano, Alaska

From September 1999 through April 2004, Shishaldin Volcano, Aleutian Islands, Alaska, exhibited a continuous and extremely high level of background seismicity. This activity consisted of many hundreds to thousands of long-period (LP; 1–2 Hz) earthquakes per day, recorded by a 6-station monitoring network around Shishaldin. The LP events originate beneath the summit at shallow depths (0–3...
Authors
Tanja Petersen, Jacqueline Caplan-Auerbach, Stephen R. McNutt

Modelling and understanding volcanic processes using high-quality seismological data Modelling and understanding volcanic processes using high-quality seismological data

At an active volcano, Very-Long-Period (VLP) seismicity (with typical periods in the range 2-100 s) reflects pressure fluctuations resulting from unsteady mass transport in the sub-surface plumbing system, and hence provides a glimpse of the internal dynamics of the volcanic edifice. Understanding the fundamental fluid-flow mechanisms involved in the generation of VLP seismic events is...
Authors
Bernard A. Chouet

LIDAR & SASW technologies for geotechnical earthquake engineering LIDAR & SASW technologies for geotechnical earthquake engineering

Geotechnical engineering methods are validated through comparison of field‐data of surface deformations and sub‐surface state properties. Recent advances in non‐invasive surface imaging and sub‐surface stiffness characterization allow us to rapidly and inexpensively map these spatial and physical properties in two and three dimensions. In this paper, we discuss new technologies used at...
Authors
Robert Kayen, Brian D. Collins

The Late-Holocene evolution of the Miseno area (south-western Campi Flegrei) as inferred by stratigraphy, petrochemistry and 40Ar/39Ar geochronology:Chapter 6 in Volcanism in the Campania Plain — Vesuvius, Campi Flegrei and Ignimb The Late-Holocene evolution of the Miseno area (south-western Campi Flegrei) as inferred by stratigraphy, petrochemistry and 40Ar/39Ar geochronology:Chapter 6 in Volcanism in the Campania Plain — Vesuvius, Campi Flegrei and Ignimb

This study on terrestrial and marine successions increases the understanding of the Late-Holocene volcanological and stratigraphical evolution of the south-western part of Campi Flegrei caldera. Stratigraphic data derived from field studies of two major tuff vents located along the coastal zone, namely Porto Miseno and Capo Miseno, clearly indicate that the Porto Miseno tuff ring...
Authors
Donatella Insinga, Andrew T. Calvert, Marvin A. Lanphere, Vincenzo Morra, Annamaria Perrotta, Marco Sacchi, Claudio Scarpati, James Saburomaru, Lorenzo Fedele

The HRSC DTM test The HRSC DTM test

The High Resolution Stereo Camera (HRSC) has been orbiting the planet Mars since January 2004 onboard the ESA Mars Express mission and delivers imagery which is being used for topographic mapping of the planet. The HRSC team is currently conducting a systematic inter-comparison of different alternatives for the production of high resolution Digital Terrain Models (DTMs) from the...
Authors
Christian Heipke, Jurgen Oberst, Jeorg Albertz, Maria Attwenger, Peter Dorninger, Egon Dorrer, M. Ewe, Stephan Gehrke, Klaus Gwinner, H. Hirschmuller, J.R. Kim, Randolph L. Kirk, H. Mayer, Jan-Peter Muller, Rajagopalan Rengarajan, M. Rentsch, R. Schmidt, Frank Scholten, J. Shan, Michael Spiegel, M. Wahlisch, Gerhard Neukum
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