The IODP Nankai Trough Seismogenic Zone Experiment

No abstract available. doi:10.2204/iodp.sd.s01.30.2007</a

IODP-ICDP Workshop examines challenges of fault zone drilling

No abstract available. doi:10.2204/iodp.sd.s01.12.2007</a

Cascadia Fore Arc Seismic Survey: Open-Access Data Available

The Cascadia subduction zone (CSZ), where the Juan de Fuca and Gorda plates subduct obliquely beneath North America at a rate of about 35 millimeters per year, poses major geological hazards to population centers of the northwestern United States. Despite the importance of the subducting slab in these hazards, the plate boundary is poorly mapped and understood, especially offshore

A perturbation expansion approach to solving the electromagnetic induction problem in three dimensions.

We address the electromagnetic induction problem for fully 3D geologic media and present a solution to the governing Maxwell equations based on a power series expansion. The coefficients in the series are computed using the adjoint method assuming an underlying homogeneous reference model. These solutions are available analytically for point dipole source terms and lead to rapid calculation of the expansion coefficients. First order solutions are presented for a model study in petroleum geophysics composed of a multi-component induction sonde proximal to a fault within a compartmentalized hydrocarbon reservoir

Operational Review of the First Wireline In Situ Stress Test in Scientific Ocean Drilling

Scientific ocean drilling’s first in situ stress measurement was made at Site C0009A during Integrated Ocean Drilling Program (IODP) Expedition 319 as part of Nankai Trough Seismogenic Zone Experiment (NanTroSEIZE) Stage 2. The Modular Formation Dynamics Tester (MDT, Schlumberger)wireline logging tool was deployed in riser Hole C0009A to measure in situ formation pore pressure, formation permeability (often reported as mobility=permeability/viscosity), and the least principal stress (S3) at several isolated depths (Saffer et al., 2009; Expedition 319 Scientists, 2010). The importance of in situ stress measurements is not only for scientific interests in active tectonic drilling, but also for geomechanical and well bore stability analyses. Certain in situ tools were not previously available for scientific ocean drilling due to the borehole diameter and open hole limits of riserless drilling. The riser-capable drillship, D/V Chikyu,now in service for IODP expeditions, allows all of the techniques available to estimate the magnitudes and orientations of 3-D stresses to be used. These techniques include downhole density logging for vertical stress, breakout and caliper log analyses for maximum horizontal stress, core-based anelastic strain recovery (ASR, used in the NanTroSEIZE expeditions in 2007–2008), and leak-off test (Lin et al., 2008) and minifrac/hydraulic fracturing (NanTroSEIZE Expedition319 in 2009). In this report, the whole operational planning process related to in situ measurements is reviewed, and lessons learned from Expedition 319 are summarized for efficient planning and testing in the future

Common Genetic Variation Near the Phospholamban Gene Is Associated with Cardiac Repolarisation: Meta-Analysis of Three Genome-Wide Association Studies

To identify loci affecting the electrocardiographic QT interval, a measure of cardiac repolarisation associated with risk of ventricular arrhythmias and sudden cardiac death, we conducted a meta-analysis of three genome-wide association studies (GWAS) including 3,558 subjects from the TwinsUK and BRIGHT cohorts in the UK and the DCCT/EDIC cohort from North America. Five loci were significantly associated with QT interval at P<1×10$^{−6}$. To validate these findings we performed an in silico comparison with data from two QT consortia: QTSCD (n = 15,842) and QTGEN (n = 13,685). Analysis confirmed the association between common variants near NOS1AP (P = 1.4×10$^{−83}$) and the phospholamban (PLN) gene (P = 1.9×10$^{−29}$). The most associated SNP near NOS1AP (rs12143842) explains 0.82% variance; the SNP near PLN (rs11153730) explains 0.74% variance of QT interval duration. We found no evidence for interaction between these two SNPs (P = 0.99). PLN is a key regulator of cardiac diastolic function and is involved in regulating intracellular calcium cycling, it has only recently been identified as a susceptibility locus for QT interval. These data offer further mechanistic insights into genetic influence on the QT interval which may predispose to life threatening arrhythmias and sudden cardiac death