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Abstract Several methods for finite element modelling and analysis of tubular welded joints are described in various design codes. These codes provide specific recommendations for modelling of the welded joints, using simple weld geometries. In this paper, experimental strain range results from two full-scale semi-automatically welded K-nodes tests are compared to corresponding finite element models. Three dimensional (3D) scans of the weld surfaces have been developed for the automatically welded K-joints. These 3D scans are included in the finite element (FE) models to determine the accuracy of the FE models. Some discrepancies are observed between finite element predictions and test results. Finite element model updating has been applied to improve the accuracy of the developed finite element models. The results are compared to a FE model with a simple weld geometry based on common offshore design codes and a FE model without any modelled weld. The results show that the FE model with 3D scanned welds are more accurate than the other FE models. The precise location of weld toe in the 3D scanned weld is difficult to locate in the FE model, thus stochastic finite element modelling is performed to analyse the probabilistic hot-spot stresses. The results show large variations in the hot-spot stresses. It can be concluded that it is necessary to evaluate the probabilistic nature of stresses for calculating fatigue lives of welded tubular joints in offshore structures.

Earthquake-triggered landslides significantly contribute to worsening the impact of seismic events; thus, comprehensive landslide inventories are essential for improving seismic hazard assessment. During complex seismic sequences, landslides are triggered by more than one event and the final inventory reflects the spatial and temporal evolution of the sequence. Here, I analyze the landslides triggered by the 2018 Lombok (Indonesia) seismic sequence. I use high-resolution satellite imagery to map 4823 landslides triggered after the 05/08/2018 event (Mw 6.9) and 9319 landslides after the 19/08/2018 event (Mw 6.9). I analyze the distribution and evolution over time of landslide density and landslide area percentage. Despite the significant increase in number and cumulative area of the landslides, the 05/08 and 19/08 events share the maximum dimension of individual landslides; this suggests that the maximum intensity is equal for the two events, i.e., X on the Environmental Scale Intensity scale. I compare the distribution of landslides with macroseismic information provided by eyewitnesses through online questionnaires. Finally, I investigate the role of earthquake environmental effects within seismic sequences, showing that effects on the natural environment provide complementary information with respect to traditional intensity and felt reports.

Particle composition data for PM10 samples collected at an urban background location in Elche in southeastern Spain from December 2004 to November 2005 were analysed to provide source identification and apportionment. A total of 120 samples were collected and analysed by Particle Induced X-ray Emission (PIXE) and ion chromatography. Positive matrix factorization (PMF) was used to estimate sources profiles and their mass contributions. The PMF modelling identified six sources: PM10 mass was apportioned to secondary nitrate (26%), secondary sulphate (22%), local soil dust (21%), traffic (13%), sea-salt (11%) and African dust (7%). It is worth noting that PMF was able to identify a Saharan dust source even in the presence of a weighty local dust source, and to quantitatively estimate the contributions of these two sources. The African dust contribution varies, depending on the intrusion days, within a range of 5-40% of the total PM10 concentration. Without the contribution of Saharan dust, 50% of the total exceedances of the PM10 50 μg m-3 EC limit during the studied period would not have taken place. © 2008 Elsevier Ltd. All rights reserved. This work was supported by the Ministerio de Educación y Ciencia under the CGL2004-04419/CLI (RESUSPENSE) project. We would like also to thank Paul Nordstrom for his support. Peer Reviewed

The object of this paper is to describe an interesting series of igneous rocks, about ½ mile south of Tideswell, and between that village and the valley of the Wye (Geol. Surv. 1-inch map, 81 S.E.). The old marble-quarry in Tideswell Dale has been known to geologists for many years, on account of the baked columnar clay underlying the toadstone, which was at one time well exposed. Numerous excursions have been made to the quarry, and several papers have been written on it, but no detailed work appears to have been done with the view of ascertaining the relation of the toadstone to the clay and the limestone-beds. The quarry was worked about 50 years ago for its fine coralline marble, but was abandoned because of the unavoidable expense of removing a great thickness of toadstone, in order to get at the limestone below it. In 1870 a paper was read before this Society by the Rev. J. M. Mello, describing the section exposed in the quarry. In the same year Mr. Edward Wilson and Mr. Edwin Brown each contributed a paper on the same subject to the Geological Magazine. According to these observers, a bed of clay, which was often columnar, rested on the coralline marble. It varied in thickness from 5 to 12 feet, and the columns in it sometimes attained a length of 8 or 9 feet, and a breadth of 6 inches. Above the clay was a band of vesicular and amygdaloidal toadstone from 1 to

[1] Tomographic images constrain the existence of a subducted seamount beneath the Gulf of Nicoya, Costa Rica. The subducted seamount is found at a depth of 30 km within the rupture area of the March 25, 1990, Mw = 7.0 Gulf of Nicoya earthquake. The Gulf of Nicoya earthquake was a typical thrust-type subduction earthquake and occurred on a shallow dipping thrust fault parallel or along the boundary between the subducting Cocos plate and the overriding plate. Precise relocation of the mainshock and its aftershocks in a 3-D P-wave velocity model shows that the area of the mainshock rupture is coincident with the imaged subducted seamount. Most of the aftershocks are relocated within or close to the inferred subducted seamount above the subducting oceanic plate. We interpret the subducted seamount as an asperity whose rupture caused the 1990 Gulf of Nicoya earthquake.

A least squares non-parametric discovery process model has been developed recently for assessing petroleum resources in mature plays with complex size distribution characteristics. Applications of this model to oil plays in the Colorado Group suggests that these techniques can be used to assess petroleum plays composed of a mixture of pools comprising both conventional and unconventional petroleum accumulations. We use the Cardium oil play of the Colorado Group in the Western Canada Sedimentary Basin to illustrate use of the non-parametric approach for such a mixed petroleum play. Our Colorado Group resource assessment indicates a large remaining oil resource potential in this petroleum system, largely in tight unconventional reservoirs.

Pseudo-wells are computer-generated one-dimensional reflection sequences, or stratigraphic sequences. The simulation of pseudo-wells has been studied by many workers because of their potential benefits to seismic studies (Sherrif, 1992). We recognise three areas of application: • seismic reservoir characterisation studies • feasibility studies and sensitivity analysis • testing seismic inversion algorithms

Abstract The direction of the maximum shear stress on any plane can be determined graphically from the traction vector. The orientation and magnitude of this vector are found from a fundamental property of symmetric tensors of second rank. Exactly the same method can be used to find the direction of the shear strain associated with any line.