Detecting remotely triggered temporal changes around the Parkfield section of the San Andreas fault

Detecting temporal changes in fault zone properties at seismogenic depth have been a long-sought goal in the seismological community for many decades.Recent studies based on waveform analysis of repeating earthquakes have found clear temporal changes in the shallow crust and around active fault zones associated with the occurrences of large nearby and teleseismic earthquakes.However,repeating earthquakes only occur in certain locations and their occurrence times cannot be controlled,which may result in inadequate sampling of the interested regions or time periods.Recent developments in passive imaging via auto-and cross-correlation of ambient seismic wavefields (e.g.,seismic noise,earthquake coda waves) provide an ideal source for continuous monitoring of temporal changes around active fault zones.Here we conduct a systematic search of temporal changes along the Parkfield section of the San Andreas fault by cross-correlating relatively high-frequency (0.4-1.3 Hz) ambient noise signals recorded by 10 borehole stations in the High Resolution Seismic Network.After using stretch/compressed method to measure the delay time and the decorrelation-index between the daily noise cross-correlation functions (NCCFs),we find clear temporal changes in the median seismic velocity and decorrelation-index associated with the 2004 M6.0 Parkfield earthquake.We also apply the same procedure to the seismic data around five regional/teleseismic events that have triggered non-volcanic tremor in the same region,but failed to find any clear temporal changes in the daily NCCFs.The fact that our current technique can detect temporal changes from the nearby but not regional and teleseismic events,suggests that temporal changes associated with distance sources are very subtle or localized so that they could not be detected within the resolution of the current technique (～0.2%).     

Petrography and provenance of the Early Permian Fluvial Warchha Sandstone,Salt Range,Pakistan

The Warchha Sandstone of the Salt Range of Pakistan is a continental succession that accumulated as part of a meandering, fluvial system during Early Permian times. Several fining-upward depositional cycles are developed, each of which is composed of conglomerate, cross-bedded sandstone and, in their upper parts, bioturbated siltstone and claystone units with distinctive desiccation cracks and carbonate concretions. Clast lithologies are mainly of plutonic and low-grade metamorphic origin, with an additional minor sedimentary component. Textural properties of the sandstone are fine- to coarse-grained, poorly to moderately sorted, sub-angular to sub-rounded, and with generally loose packing. Based on modal analyses, the sandstone is dominantly a feldspathoquartzose (arkose to sub-arkose). Detrital constituents are mainly composed of monocrystalline quartz, feldspars (more K-feldspar than plagioclase) and various types of lithic clasts. XRD and SEM studies indicate that kaolinite is the dominant clay mineral and that it occurs as both allogenic and authigenic forms. However, illite, illite-smectite mixed layer, smectite and chlorite are also recognised in both pores and fractures. Much of the kaolinite was likely derived by the severe chemical weathering of previously deposited basement rocks under the influence of a hot and humid climate. Transported residual clays deposited as part of the matrix of the Warchha Sandstone show coherent links with the sandstone petrofacies, thereby indicating the same likely origin. Illite, smectite and chlorite mainly occur as detrital minerals and as alteration products of weathered acidic igneous and metamorphic rocks. Based primarily on fabric relationship, the sequence of cement formation in the Warchha Sandstone is clay (generally kaolinite), iron oxide, calcareous and siliceous material, before iron-rich illite and occasional mixed layer smectite–illite and rare chlorite. Both petrographic analysis and field characteristics of the sandstone indicate that the source areas were characterised by uplift of a moderate to high relief continental block that was weathered under the influence of hot and humid climatic conditions. The rocks weathered from the source areas included primary granites and gneisses, together with metamorphic basement rocks and minor amounts of sedimentary rocks. Regional palaeogeographic reconstructions indicate that much of the Warchha Sandstone detritus was derived from the Aravalli and Malani ranges and surrounding areas of the Indian Craton to the south and southeast, before being transported to and deposited within the Salt Range region under the influence of a semi-arid to arid climatic regime.     

Depositional history and sequence stratigraphy of Tirgan formation (Barremian-Aptian) in central Kopet Dagh, NE Iran

The Tirgan Formation (Barremian — Aptian) is exposed in the Kopet Dagh in northeast Iran. Two stratigraphic sections in Radkan and Chenaran were measured. Their thickness are 238 m and 119 m, respectively. This formation in measured sections consists of three parts (including lower carbonate, middle limy shale — marl and upper carbonate rocks). Based on study of 164 thin-sections, 15 carbonate and 2 siliciclastic lithofacies have been identified. Carbonate lithofacies are deposited in a ramp platform in fore shoal, shoal, lagoon and tidal flat environments. Sea level changes during lower Cretaceous led to the formation of different large-scale depositional sequences Radkan (two) and Chenaran (two) respectively. The present study highlights the reconstruction of tectonic history of the area during lower Cretaceous.     

Arabs versus Jews in Galilee: Competition for regional resources

This paper suggests that the State of Israel is neither pluralistic nor neutral when it comes to the allocation of regional resources between the two groups of its citizenry, Jewish and Arab. The study focuses on the state's N region, Galilee, where the unequal distribution of land, water, and local budgets as regional resources between Jewish and Arab settlements reflects a geography of power along lines of ethnic cleavage. Rather than being a neutral agent in resource distribution and allocation, the central government plays a key role in allocatinal policies distinctly skewed in favor of the Jewish population in Galilee, resulting in highly uneven development patterns and other disparities.Paper originally presented at the IBG Annual conference, Glasgow, 3–6 January 1990     

Inference of total ozone from photometric measurements of sky radiation

Summary Ground-based photometric measurements of spectral sky radiation have been made using a simple filter instrument. Sky radiation intensities measured in the solar vertical at =3200 Å and 3600 Å are compared to infer total ozone. A model of multiple scattering Rayleigh atmosphere serves as a primary reduction parameter. Spectral measurements of all-sky radiance distribution are used to study the effects of haze and clouds on the inference of total ozone. The brightness distribution of clear and overcast sky in ultraviolet is also described.     

The development of the ‘planned bedouin settlement’ in Israel 1964–1982: evaluation and characteristics

Tribal traditions are facing a severe crisis in modern society. The bedouin in Israel form a small group (13%) within the state's Arab minority, and they completed their transition stage towards settled habits in the middle of the present century with the establishment of a relatively high number of villages and hamlets. For a variety of reasons such a high number of settlements is considered ‘undesirable’ by the state. It is the object of this paper to examine the state planning of bedouin settlement as a part of the policy of concentrating bedouin groups. It also sheds light on tribal reaction towards this policy.     

The spatial pattern of Bedouin Sedentarization in Israel

The bedouin in Israel form a small group (13%) within the state's Arab minority, and they completed their transition stage towards settled habits in the middle of the present century with the establishment of a relatively high number of villages and hamlets. It is the object of this paper to examine and define the nature of these patterns of rural settlements, which emerged in the two distinctive areas of Galilee and the Negev.The discussion in this paper is confined to the period of the state of Israel (1948–83), when changes in both the processes and the patterns of bedouin sedentarization took place under entirely new political conditions. After the establishment of the Jewish State of Israel in 1948, both Galilee and Negev bedouin sedentarization was completed within a period of a single decade (1950–60). However, the sedentarization pattern has further evolved during the past two decades and is likely to continue to do so until the end of the present century.In the Israeli period, the pattern of bedouin sedentarization has developed in two distinct directions. First, the bedouin themselves have built permanent structures for residential purposes, a process usually referred to as spontaneous bedouin settlement. Secondly, the state authorities have planned and established settlements. In this planned bedouin settlement, the state has been dominant in shaping the pattern. It is important to note that most bedouin settlement in Israel belong in the first category where the whole tribe or individual groups were the initiators of their settlements. This paper which was written by an author who belongs to the bedouin community, is based mostly upon fresh evidence from field research data, and is the first attempt to indicate the importance of the role of the state in shaping the settlement pattern. It is hoped to contribute to the study of nomadism as well as to the study of the Arabs in Israel.Paper presented at the 25th International Geographical Congress Paris 27–31 August 1984. The author would like to thank the Centre for Arab Heritage without whose support his attendance at this conference would not have been possible.     

Numerical simulation of bolt‐supported tunnels by means of a multiphase model conceived as an improved homogenization procedure

This paper examines the possibility of applying a homogenization procedure to analyze the convergence of a tunnel reinforced by bolts, regarded as periodically distributed linear inclusions. Owing to the fact that a classical homogenization method fails to account for the interactions prevailing between the bolts and the surrounding ground and thus tends to significantly overestimate the reinforcement effect in terms of convergence reduction, a so‐called multiphase model is presented and developed, aimed at improving the classical homogenization method. Indeed, according to this model, the bolt‐reinforced ground is represented at the macroscopic scale as the superposition of two mutually interacting continuous phases, describing the ground and the reinforcement network, respectively. It is shown that such a multiphase approach can be interpreted as an extension of the homogenization procedure, thus making it possible to capture the ground–reinforcement interaction in a proper way, provided the constitutive parameters of the model and notably those relating to the interaction law can be identified from the reinforced ground characteristics. The numerical implementation of this model in a finite element method‐based computer code is then carried out, and a first illustrative application is finally presented. Copyright © 2008 John Wiley & Sons, Ltd.