RV Sonne Cruise 200, 11 Jan-11 Mar 2009. Jakarta - Jakarta

All plate boundaries are divided into segments - pieces of fault that are distinct from oneanother, either separated by gaps or with different orientations. The maximum size of anearthquake on a fault system is controlled by the degree to which the propagating rupture cancross the boundaries between such segments. A large earthquake may rupture a whole segmentof plate boundary, but a great earthquake usually ruptures more than one segment at once.The December 26th 2004 MW 9.3 earthquake and the March 28th 2005 MW 8.7 earthquakeruptured, respectively, 1200–1300 km and 300–400 km of the subduction boundary betweenthe Indian-Australian plate and the Burman and Sumatra blocks. Rupture in the 2004 eventstarted at the southern end of the fault segment, and propagated northwards. The observationthat the slip did not propagate significantly southwards in December 2004, even though themagnitude of slip was high at the southern end of the rupture strongly suggests a barrier at thatplace. Maximum slip in the March 2005 earthquake occurred within ~100 km of the barrierbetween the 2004 and 2005 ruptures, confirming both the physical importance of the barrier,and the loading of the March 2005 rupture zone by the December 2004 earthquake.The Sumatran Segmentation Project, funded by the Natural Environment Research Council(NERC), aims to characterise the boundaries between these great earthquakes (in terms of bothsubduction zone structure at scales of 101-104 m and rock physical properties), record seismicactivity, improve and link earthquake slip distribution to the structure of the subduction zoneand to determine the sedimentological record of great earthquakes (both recent and historic)along this part of the margin. The Project is focussed on the areas around two earthquakesegment boundaries: Segment Boundary 1 (SB1) between the 2004 and 2005 ruptures atSimeulue Island, and SB2 between the 2005 and smaller 1935 ruptures between Nias and theBatu Islands.Cruise SO200 is the third of three cruises which will provide a combined geophysical andgeological dataset in the source regions of the 2004 and 2005 subduction zone earthquakes.SO200 was divided into two Legs. Leg 1 (SO200-1), Jakarta to Jakarta between January 22ndand February 22nd, was composed of three main operations: longterm deployment OBSretrieval, TOBI sidescan sonar survey and coring. Leg 2 (SO200-2), Jakarta to Jakarta betweenFebruary 23rd and March 11th, was composed of two main operations: Multichannel seismicreflection (MCS) profiles and heatflow probe transects

Diagnostic Applications for Micro-Synchrophasor Measurements

This report articulates and justifies the preliminary selection of diagnostic applications for data from micro-synchrophasors (µPMUs) in electric power distribution systems that will be further studied and developed within the scope of the three-year ARPA-e award titled Micro-synchrophasors for Distribution Systems

Geomechanical Analysis of Sedimentary Layering as a Structural Control on Fault Propagation

Deformation associated with normal fault propagation and displacement places controls on the distribution and flow of sub-surface fluids. With a better understanding of how sedimentary units deform in response to a propagating fault, I can better predict how fluids might flow through the system at initial stages of displacement. To elucidate the role of sedimentary layering on fault tip propagation, I use ABAQUS/Standard to conduct a finite element analysis of a propagating normal fault to identify patterns of stress distribution and accumulation. While holding material properties constant (e.g., Young’s Modulus, Poisson’s Ratio, dilation angle, and the internal angle of friction), I simulate the initial stages of plastic failure in front of a normal fault tip propagating at 60° through bedded sandstone at low levels ( \u3c 0.09 m displacement). I test the effects of incrementally increasing the number of mechanical layers from a single 20-m thick layer to five 4-m thick layers. I find that the presence of layering allows for simultaneous, but discontinuous, plastic failure in multiple locations ahead of a propagating fault tip. Additionally, although inter-layer stress accumulation is hindered by an increased number of layers, elevated regions of maximum stress occur further ahead of the propagating fault tip with an increased number of layers. Additionally, I show that the coefficient of friction between beds controls the angle at which off-fault-plane stress develops. My results show that mechanical layering systematically re-distributes stress ahead of a propagating fault tip so that a section of sandstone with multiple layers will fracture differently than a single massive bed. This predictable mechanical behavior is likely to influence the development of fluid conduits associated with fracturing during the early stages of normal fault propagation, a finding that has implications for the evolution of permeability structure of real-world fault zones in the subsurface

Understanding European policy on the internal market for electricity and gas: evaluation of the Electricity and Gas Directives

This report examines the various inputs to the Electricity and Gas Directives review