Deep structure of the southern Rhinegraben area from seismic refraction investigations

A joint interpretation of all seismic-refraction profiles in the southern part of the Rhinegraben area is presented. A time-term analysis of all Pg-arrivals reveals the topography of the crystalline basement and provides an average velocity of 6.0 km/s for the uppermost crust. The crust-mantle boundary is clearly elevated in the Rhinegraben rift system forming an arch with a span of 150-180 km and reaching a depth of only 25 km at the flanks of the graben proper. The velocity of P-waves in the uppermost mantle is 8.0-8.1 km/s. Below the flanks of the graben, the crust-mantle boundary is formed by a first-order discontinuity. Within the graben proper it is replaced by a transition zone of 4 km thickness with the strongest velocity gradient at a depth of 21 km. This transition zone is regarded as region of crust-mantle interaction and seems to be confined to the graben proper.         ARK: https://n2t.net/ark:/88439/y074159 Permalink: https://geophysicsjournal.com/article/71 &nbsp

Upper Crustal Structure from the Santa Monica Mountains to the Sierra Nevada, Southern California: Tomographic Results from the Los Angeles Regional Seismic Experiment, Phase II (LARSE II)

In 1999, the U.S. Geological Survey and the Southern California Earthquake Center (SCEC) collected refraction and low-fold reflection data along a 150-km-long corridor extending from the Santa Monica Mountains northward to the Sierra Nevada. This profile was part of the second phase of the Los Angeles Region Seismic Experiment (LARSE II). Chief imaging targets included sedimentary basins beneath the San Fernando and Santa Clarita Valleys and the deep structure of major faults along the transect, including causative faults for the 1971 M 6.7 San Fernando and 1994 M 6.7 Northridge earthquakes, the San Gabriel Fault, and the San Andreas Fault. Tomographic modeling of first arrivals using the methods of Hole (1992) and Lutter et al. (1999) produces velocity models that are similar to each other and are well resolved to depths of 5-7.5 km. These models, together with oil-test well data and independent forward modeling of LARSE II refraction data, suggest that regions of relatively low velocity and high velocity gradient in the San Fernando Valley and the northern Santa Clarita Valley (north of the San Gabriel Fault) correspond to Cenozoic sedimentary basin fill and reach maximum depths along the profile of ∼4.3 km and >3 km, respectively. The Antelope Valley, within the western Mojave Desert, is also underlain by low-velocity, high-gradient sedimentary fill to an interpreted maximum depth of ∼2.4 km. Below depths of ∼2 km, velocities of basement rocks in the Santa Monica Mountains and the central Transverse Ranges vary between 5.5 and 6.0 km/sec, but in the Mojave Desert, basement rocks vary in velocity between 5.25 and 6.25 km/sec. The San Andreas Fault separates differing velocity structures of the central Transverse Ranges and Mojave Desert. A weak low-velocity zone is centered approximately on the north-dipping aftershock zone of the 1971 San Fernando earthquake and possibly along the deep projection of the San Gabriel Fault. Modeling of gravity data, using densities inferred from the velocity model, indicates that different velocity-density relationships hold for both sedimentary and basement rocks as one crosses the San Andreas Fault. The LARSE II velocity model can now be used to improve the SCEC Community Velocity Model, which is used to calculate seismic amplitudes for large scenario earthquakes

Sex-related differences in oncologic outcomes, operative complications and health-related quality of life after curative-intent oesophageal cancer treatment: multicentre retrospective analysis

Background: Oesophageal cancer, in particular adenocarcinoma, has a strong male predominance. However, the impact of patient sex on operative and oncologic outcomes and recovery of health-related quality of life is poorly documented, and was the focus of this large multicentre cohort study. Methods: All consecutive patients who underwent oncological oesophagectomy from 2009 to 2015 in the 20 European iNvestigation of SUrveillance after Resection for Esophageal cancer study group centres were assessed. Clinicopathologic variables, therapeutic approach, postoperative complications, survival and health-related quality of life data were compared between male and female patients. Multivariable analyses adjusted for age, sex, tumour histology, treatment protocol and major complications. Specific subgroup analyses comparing adenocarcinoma versus squamous cell cancer for all key outcomes were performed. Results: Overall, 3974 patients were analysed, 3083 (77.6%) male and 891 (22.4%) female; adenocarcinoma was predominant in both groups, while squamous cell cancer was observed more commonly in female patients (39.8% versus 15.1%, P < 0.001). Multivariable analysis demonstrated improved outcomes in female patients for overall survival (HRmales 1.24, 95% c.i. 1.07 to 1.44) and disease-free survival (HRmales 1.22, 95% c.i. 1.05 to 1.43), which was caused by the adenocarcinoma subgroup, whereas this difference was not confirmed in squamous cell cancer. Male patients presented higher health-related quality of life functional scores but also a higher risk of financial problems, while female patients had lower overall summary scores and more persistent gastrointestinal symptoms. Conclusion: This study reveals uniquely that female sex is associated with more favourable long-term survival after curative treatment for oesophageal cancer, especially adenocarcinoma, although long-term overall and gastrointestinal health-related quality of life are poorer in women

Crustal structure of the Rhenish Massif and adjacent areas; a reinterpretation of existing seismic-refraction data

Most of the existing seismic-refraction profiles in the Rhenish Massif/Rhenohercynian zone of Western Germany have been jointly reinterpreted using traveltime and amplitude information. The general pattern of observed phases can be divided into three types; each type corresponds to a distinct kind of velocity structure. Type I: Throughout the central Rhenish Massif and the adjacent Hessische Senke a strong P-phase reflection from the crust-mantle boundary is recorded in regions where no major volcanic features are crossed by the lines of seismic observations. The average crustal thickness is 28-29 km, the average crustal velocity (excepting sediments) is 6.2-6.3 km/sec, and the crust is nearly homogeneous. This structure is here referred to as the Rhenohercynian crustal model. Type II: Beneath the southern part of the Rhenish Massif and two areas in the northeast and southeast some structure within the crust is evident. Both an intracrustal and the Moho discontinuities are evidenced by strong reflected phases, the Moho reflection being the stronger one. Along the profiles crossing major volcanic features such as Vogelsberg and central Westerwald, but not beneath the eastern Eifel, the M-discontinuity is heavily disrupted or "smeared" and an intermediate intracrustal boundary at about 20 km depth forms the main reflector for seismic waves. Beneath this boundary the velocity increases gradually from about 7 km/sec to upper-mantle velocities. Type III: For profiles crossing the northern Rhine Graben area as well as for a line from the Siebengebirge through the Rhenish Massif to the north, east of the Lower Rhine basin, the observed phases indicate only one major seismic boundary at a depth of about 23 km where the velocity increases rapidly to 7.3 km/sec. Below this boundary the velocity increases gradually with depth reaching 8 km/sec at 27-28 km. The occurrence of types I, II, and III can be roughly correlated with tectonic setting. The Pn phase is recorded with variable success and disappears completely on a profile passing the eastern Eifel volcanics, but is clear on the lines through Vogelsberg and central Westerwald. The petrographic differences between these volcanics appear such to be reflected in the behaviour of the seismic waves. Cross sections and areal views are used to display the variations in crustal and upper mantle velocity structure. &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; ARK: https://n2t.net/ark:/88439/y002726 Permalink: https://geophysicsjournal.com/article/180 &nbsp