Neotectonics and Palaeoseismicity in North West Scotland

Detailed field investigation has revealed a number of faults that display late Quaternary movement in the formerly glaciated Highlands of North West Scotland. These include NE-orientated reverse, WNW- to NW-orientated sinistral strike-slip and N- to NNW-orientated dextral strike-slip faults. In all cases movement has occurred along pre-existing basement faults. The faults offset late Quaternary morphological features, including drainage courses, and disrupt late- and post-glacial sediments. Electron Spin Resonance was used in an attempt to accurately age-date the fault movements. Although this proved unsuccessful, this study showed the limitations of using this technique in relation to fault dating studies. Fault movement was accompanied by coseismic ground deformation as shown by the density of seismically-triggered slope failures and seismite soft sediment deformation around the fault ground ruptures. The areal distribution of these deformation features and the dimensions of the associated fault ruptures indicate elevated levels of seismic activity, with events up to Ms 7.0. This is considerably greater than the levels of seismic activity experienced at present. Faulting was associated with a period of rapid isostatic uplift during and immediately following the decay of the last glacial episode, the Main Late Devensian, c. 13,000 years BP. A short-lived glacial readvance, the Loch Lomond Stadial, lasting from c. 11,000 to 10,300 years BP, caused temporary redepression of the crust halting uplift and faulting prior the main period of fault activity post-10,300 years BP. Although the majority of fault movement occurred in the immediate post-glacial period, significant fault movement has occurred as recently as 2,400 years BP. Faulting resulted from the sudden release of glacial loading stresses and tectonic stresses stored during ice-sheet residence. Elevated pore fluid pressure is seen to be important in the timing and sustaining of fault movement outwith the immediate post-glacial period. Such elevated pore fluid pressure also allowed the reactivation of faults that were less favourably orientated with respect to the regional stress field. This evidence for fault movement and seismic activity in the early part of the Holocene is compared with present day seismotectonic activity and used to predict the present day risk of ground rupture and damaging earthquake activity in the UK as a whole. It is proposed that present day crustal movements result from the actions of the NW European regional stress field, the effects of glacially-induced stresses now having decayed to insignificant levels

Recent Paleoseismic Investigations in Northern and Western Thailand

Recent paleoseismic investigations have identified a number of active faults in Northern and Western Thailand. Northern Thailand is an intraplate basin and range province, comprised of north-south-trending Cenozoic intermontane grabens and half grabens, bounded by north- to northwest-striking normal to normal-oblique faults and northeast-striking left-lateral strike-slip faults. The basin-bounding normal faults are marked by steep, linear range fronts with triangular facets and wineglass canyons and have slip rates of 0.1 to 0.8 mm/yr. Based on limited data, the average vertical displacement-per-event is about 1.0 to 1.5 m. These faults are characterized by recurrence intervals of thousands to tens of thousands of years and are capable of generating earthquakes up to moment magnitude (M) 7, and larger. The northeast-striking strike-slip faults are marked by shutter ridges, and deflected drainages. Slip rates are 3 mm/yr or less. Western Thailand is dissected by a number of northwest- and north-northwest-striking, right-lateral strike-slip faults related to the Sagaing Fault in Myanmar. Although showing much less activity than the faults in neighboring Myanmar, these faults display abundant evidence for late Quaternary movement, including shutter ridges, sag ponds, and laterally offset streams. The slip rate on these faults is estimated to be 0.5 to 2.0 mm/yr. These faults are considered capable of generating maximum earthquakes of up to M 71/2

Strategizing and organizing in pluralistic contexts

In this article, the concept of pluralism is used to expose variations in the relationship between organizing and strategizing and the consequences of these variations for managerial practice. Pluralistic contexts are those that are shaped by the divergent goals and interests of different groups inside and outside the organization. Internally, these divergent interests result in multiple organizing processes, while the interests of external stakeholders lead to multiple strategic goals and objectives. Despite the Fact that innate pluralism and the consequent complexity of strategizing and organizing processes are experienced by many organizations in the 21st century, pluralism has been inadequately examined in organisation studies and virtually ignored in the strategy literature. Having defined pluralism and explained its implications for strategizing and organizing practices and processes within organizations, three relevant questions are posed for investigating the nature of organizing and strategizing in pluralistic contexts. Case examples from the public sector, professional services and regulated industries are utilized to provide insights into these questions, and derive a framework that enables the drivers and potential problems of the interdependence between strategizing and organizing to be better understood. Practical implications for managing this interdependence are drawn

Preliminary Observations of Geotechnical Failures During the 21 May 2003 M 6.8 Boumerdes, Earthquake, Algeria

At 18:44 UTC (19:44 local time) on May 21, 2003, a strong, shallow earthquake of Moment Magnitude (M) 6.8 shook northern Algeria and caused damage in five provinces in the north-central section of the country. Damage was reported over an area about 100 km long and 35 km wide, centered on the city of Boumerdes. The hardest hit areas were in the coastal province of Boumerdes, mainly in the cities of Boumerdes, Zemmouri and Thenia. The earthquake appears to have been generated by an offshore south-dipping thrust fault oriented N54°E extending for about 35 km from Dellys to Corso. The fault rupture was bilateral, with a greater asymmetry to the southwest. The ground motions recorded from the mainshock were significantly higher than median values predicted by standard attenuation relationships. Liquefaction and lateral spreading occurred near the Isser River and areas with extensive beach sand deposits. In the port of Algiers, nine piers suffered damage where liquefaction, loss of ground support, and lateral displacement (seaward movements) of the bulkheads were pervasive. Cracks developed on the Keddara and Beni Amrane Dams and the water line running from the Keddara Dam to the Boudouaou water treatment plant suffered damage at two locations

Combined Thermal Weakening and Mechanical Disintegration of Hard Rock

This investigation of the combined effects of thermal weakening and mechanical disintegration (thermomechanical fragmentation) was initiated with a view toward better understanding of the processes required for more rapidly and economically fragmenting or excavating hard rock. Boring machines for utility tunnels, transportation tunnels or mining operations may be able to utilize the advantages of processes such as thermomechanical fragmentation. Secondary fragmentation or rock crushing processes also can conceivably employ the data obtained from this study

Re-emerging syphilis: a detrended correspondence analysis of the behaviour of HIV positive and negative gay men

BACKGROUND: Recent syphilis outbreaks in the UK have raised serious concerns about the sexual health of the population. Moreover, syphilis appears more likely to facilitate HIV transmission than any other sexually transmitted infection (STI). METHODS: The sexual and other risk behaviour of a sample of HIV positive and negative gay men with and without syphilis was subjected to a detrended correspondence analysis (DCA). RESULTS: A DCA plot was used to illustrate similarity of individuals in terms of their behaviours, regardless of their infection status. The majority of those with syphilis (78%; 18/23) fell into a high-risk group with more partners, and use of anonymous sex venues and drugs during sex. However, 16% of uninfected controls (8/49) and 62% of HIV positive individuals without syphilis (8/13) also fell into this high-risk group. CONCLUSIONS: Using a statistical technique that is novel for this type of investigation, we demonstrate behavioural overlaps between syphilis-infected individuals in an ongoing UK outbreak and uninfected HIV positive and negative controls. Given the high-risk behaviour of a significant proportion of uninfected individuals, ongoing transmission of syphilis and HIV in this population seems likely

A multi-disciplinary approach to assess the impact of global climate change on infrastructure in cold regions

Imperial College London is researching with BP some potential impacts of future climate change. BP has a significant number of facilities in cold high-latitude regions, where global climate models predict significant rises in air and ground surface temperature. This could impact on the state and extent of permafrost, potentially posing risks to facilities, infrastructure, and operations (ACIA 2005). The paper reviews the research, focusing on an exemplar study region in eastern Siberia. The key elements included: (1) Developing an approach to provide a best estimate of future climate change. (2) An engineering geological appraisal of the ground conditions in the study region. (3) Performing a parametric study of geothermal conditions in the study region using finite element thermal analyses. (4) Developing a Thermal-Hydraulic-Mechanical modeling approach for assessment of climate change impact on specific engineering facilities. (5) Developing a methodology for incorporating potential climate change considerations into engineering decision-making and design.Postprint (published version

The Grizzly, September 17, 1982

New Ursinus Students Welcomed • Lantern Needs Associate Editor • Vandalism at Myrin • Administration Alterations • Committee Needs Chairmen • Folk Festival Summer Fun • Forum Preview • Lewis on Wall Street • Fencing Anyone? • Sendai Students at UC • Changes in Wismer • USGA Notes • Field Hockey Falls to Trenton State • The Bear Pack is in Top Form, Again • Volleyball Dumps Del Val • Grizzlies Drop Football Opener • Soccer Team Loses Two Close Oneshttps://digitalcommons.ursinus.edu/grizzlynews/1081/thumbnail.jp

Dust Devil Tracks

Dust devils that leave dark- or light-toned tracks are common on Mars and they can also be found on the Earth’s surface. Dust devil tracks (hereinafter DDTs) are ephemeral surface features with mostly sub-annual lifetimes. Regarding their size, DDT widths can range between ∼1 m and ∼1 km, depending on the diameter of dust devil that created the track, and DDT lengths range from a few tens of meters to several kilometers, limited by the duration and horizontal ground speed of dust devils. DDTs can be classified into three main types based on their morphology and albedo in contrast to their surroundings; all are found on both planets: (a) dark continuous DDTs, (b) dark cycloidal DDTs, and (c) bright DDTs. Dark continuous DDTs are the most common type on Mars. They are characterized by their relatively homogenous and continuous low albedo surface tracks. Based on terrestrial and martian in situ studies, these DDTs most likely form when surficial dust layers are removed to expose larger-grained substrate material (coarse sands of ≥500 μm in diameter). The exposure of larger-grained materials changes the photometric properties of the surface; hence leading to lower albedo tracks because grain size is photometrically inversely proportional to the surface reflectance. However, although not observed so far, compositional differences (i.e., color differences) might also lead to albedo contrasts when dust is removed to expose substrate materials with mineralogical differences. For dark continuous DDTs, albedo drop measurements are around 2.5 % in the wavelength range of 550–850 nm on Mars and around 0.5 % in the wavelength range from 300–1100 nm on Earth. The removal of an equivalent layer thickness around 1 μm is sufficient for the formation of visible dark continuous DDTs on Mars and Earth. The next type of DDTs, dark cycloidal DDTs, are characterized by their low albedo pattern of overlapping scallops. Terrestrial in situ studies imply that they are formed when sand-sized material that is eroded from the outer vortex area of a dust devil is redeposited in annular patterns in the central vortex region. This type of DDT can also be found in on Mars in orbital image data, and although in situ studies are lacking, terrestrial analog studies, laboratory work, and numerical modeling suggest they have the same formation mechanism as those on Earth. Finally, bright DDTs are characterized by their continuous track pattern and high albedo compared to their undisturbed surroundings. They are found on both planets, but to date they have only been analyzed in situ on Earth. Here, the destruction of aggregates of dust, silt and sand by dust devils leads to smooth surfaces in contrast to the undisturbed rough surfaces surrounding the track. The resulting change in photometric properties occurs because the smoother surfaces have a higher reflectance compared to the surrounding rough surface, leading to bright DDTs. On Mars, the destruction of surficial dust-aggregates may also lead to bright DDTs. However, higher reflective surfaces may be produced by other formation mechanisms, such as dust compaction by passing dust devils, as this may also cause changes in photometric properties. On Mars, DDTs in general are found at all elevations and on a global scale, except on the permanent polar caps. DDT maximum areal densities occur during spring and summer in both hemispheres produced by an increase in dust devil activity caused by maximum insolation. Regionally, dust devil densities vary spatially likely controlled by changes in dust cover thicknesses and substrate materials. This variability makes it difficult to infer dust devil activity from DDT frequencies. Furthermore, only a fraction of dust devils leave tracks. However, DDTs can be used as proxies for dust devil lifetimes and wind directions and speeds, and they can also be used to predict lander or rover solar panel clearing events. Overall, the high DDT frequency in many areas on Mars leads to drastic albedo changes that affect large-scale weather patterns