Permeability changes in simulated granite faults during and after frictional sliding

Thermal–hydrological–mechanical coupling processes suggest that fault permeability should undergo dynamic change as a result of seismic slip. In igneous rocks, a fault's slip surface may have much higher permeability than the surrounding rock matrix and therefore operate as a conduit for fluids. We conducted laboratory experiments to investigate changes in fracture permeability (or transmissivity) of a fault in granite due to shear slip and cyclic heating and cooling. Our experiments showed that high initial fracture transmissivity (>10^?18 m³) was associated with a high friction coefficient and that transmissivity decreased during slip. We propose that this reduction in transmissivity reflects the presence of gouge in fracture voids, increasing the area of contact in the fault plane and reducing the hydraulic aperture. In contrast, when initial fracture transmissivity was low (<10^?18 m³), we observed that friction was lower and transmissivity increased during slip. The high transmissivity and high friction may be explained by large areas of bare rock being in contact on the slip surface. Slip velocity had little influence on the evolution of permeability, probably because gouge produced at different slip velocities had similar grain size distributions, or because gouge leaked from the slip surface. Transmissivity decreased with increasing temperature in heating tests, probably due to thermal expansion increasing normal stress on the fracture. Frictional heating did not influence transmissivity during the shearing tests.     

Behavioral Ecology and Archaeology

Behavioral ecology is the study of adaptive behavior in relation to social and environmental circumstances. Analysts working from this perspective hold that the reproductive strategies and decision-making capacities of all living organisms—including humans—are shaped by natural selection. Archaeologists have been using this proposition in the study of past human behavior for more than 30 years. Significant insights on variation in prehistoric human subsistence, life history, social organization, and their respective fossil and archaeological consequences have been among the more important results.     

New Fathoms in Scientific Exploration: The DeepWrecks Project

Modern technology lends itself to holistic exploration and widely accessible outreach. New technology allows scientists studying our planet either from space or deep under the seas, to explore and reveal both natural and cultural resources that have previously escaped our scrutiny. However, the use of these new technologies is expensive and often the exclusive tool of industrial research. Yet, these new technologies can lead the way to greater collaboration, better science and more public access. In 2003 and 2004, a landmark project, combining government agencies, industrial technology and outreach set new standards in collaborative scientific exploration. The project focused on six shipwrecks at depth in the Gulf of Mexico. The questions posed by the project illuminate how science and industry can collaborate to produce remarkable results. The papers presented in this issue form a model for deepwater exploration.     

Not Only Helpless but also Hopeless: Changing Dynamics of Urban Poverty in Turkey,the Case of Sultanbeyli,Istanbul

This paper is an attempt to understand the changing characteristics of urban poverty in Turkey since 1980. First, it analyses how the urban poor in Turkey had adopted aggressive survival strategies by strengthening their solidarity networks on religious, ethnic and cultural bases until the 2000s. Then it sheds light on how those networks have dissolved later on thanks to a set of internal and external factors and concludes that Turkey now faces deepening poverty levels and engendering new forms and dynamics of poverty. This paper is based on the Sultanbeyli district of Istanbul, a district almost entirely composed of unauthorized houses whose population grew at an unprecedented rate after 1980; and it is a perfect case for the study of issues relating to migration, urbanization and poverty in Turkish cities.     

Joining the Evangelical Club: The Movement of the Wesleyan‐Holiness Churches in Australia Along the Church‐Sect Continuum

A number of North American Wesleyan‐Holiness denominations emerged in Australia, beginning in the years following the Second World War. Some of these churches moved from being despised and marginalized sects to established denominations while others remained small and isolated, experiencing little growth. Their story demonstrates that movement along the church‐sect continuum is by no means a smooth and inevitable one. Random processes may lower or raise religious tension within the group thus affecting its movement along the continuum. The strict behavioural standards in Wesleyan‐Holiness churches have gradually been lowered and the distinctive beliefs of these groups have been eroded. Wesleyan‐Holiness churches in Australia have grown primarily through “switchers” from other denominations more than from new convert growth, so that they have become more generically “Evangelical” and less distinctively “Holiness” in their beliefs and practices.