19 research outputs found

    The significance of heat transport by shallow fluid flow at an active plate boundary: the Southern Alps, New Zealand

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    Fluid flow can influence fault behavior. Here we quantify the role of groundwater heat advection in establishing the thermal structure of the Alpine Fault, a major tectonic boundary in southern New Zealand that accommodates most of the motion between the Australian and Pacific Plates. Convergence on the Alpine Fault has rapidly uplifted the Southern Alps, resulting in high geothermal gradients and a thin seismogenic zone. A new equilibrium temperature profile from the 818-m-deep Deep Fault Drilling Project 2B borehole has been interrogated using one-dimensional analytical models of fluid and rock advection. Models indicate a total heat flux of 720-mW m2 results from groundwater flow with Darcy velocities approximating to 7.8 × 1010 m s1. Groundwaters advect significantly more heat than rock advection in the shallow orogen (<6-km depth) and are the major control on the subsurface temperature field

    Petrophysical, Geochemical, and Hydrological Evidence for Extensive Fracture-Mediated Fluid and Heat Transport in the Alpine Fault's Hanging-Wall Damage Zone

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    Fault rock assemblages reflect interaction between deformation, stress, temperature, fluid, and chemical regimes on distinct spatial and temporal scales at various positions in the crust. Here we interpret measurements made in the hanging-wall of the Alpine Fault during the second stage of the Deep Fault Drilling Project (DFDP-2). We present observational evidence for extensive fracturing and high hanging-wall hydraulic conductivity (∌10−9 to 10−7 m/s, corresponding to permeability of ∌10−16 to 10−14 m2) extending several hundred meters from the fault's principal slip zone. Mud losses, gas chemistry anomalies, and petrophysical data indicate that a subset of fractures intersected by the borehole are capable of transmitting fluid volumes of several cubic meters on time scales of hours. DFDP-2 observations and other data suggest that this hydrogeologically active portion of the fault zone in the hanging-wall is several kilometers wide in the uppermost crust. This finding is consistent with numerical models of earthquake rupture and off-fault damage. We conclude that the mechanically and hydrogeologically active part of the Alpine Fault is a more dynamic and extensive feature than commonly described in models based on exhumed faults. We propose that the hydrogeologically active damage zone of the Alpine Fault and other large active faults in areas of high topographic relief can be subdivided into an inner zone in which damage is controlled principally by earthquake rupture processes and an outer zone in which damage reflects coseismic shaking, strain accumulation and release on interseismic timescales, and inherited fracturing related to exhumation

    Antiinflammatory Therapy with Canakinumab for Atherosclerotic Disease

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    Background: Experimental and clinical data suggest that reducing inflammation without affecting lipid levels may reduce the risk of cardiovascular disease. Yet, the inflammatory hypothesis of atherothrombosis has remained unproved. Methods: We conducted a randomized, double-blind trial of canakinumab, a therapeutic monoclonal antibody targeting interleukin-1ÎČ, involving 10,061 patients with previous myocardial infarction and a high-sensitivity C-reactive protein level of 2 mg or more per liter. The trial compared three doses of canakinumab (50 mg, 150 mg, and 300 mg, administered subcutaneously every 3 months) with placebo. The primary efficacy end point was nonfatal myocardial infarction, nonfatal stroke, or cardiovascular death. RESULTS: At 48 months, the median reduction from baseline in the high-sensitivity C-reactive protein level was 26 percentage points greater in the group that received the 50-mg dose of canakinumab, 37 percentage points greater in the 150-mg group, and 41 percentage points greater in the 300-mg group than in the placebo group. Canakinumab did not reduce lipid levels from baseline. At a median follow-up of 3.7 years, the incidence rate for the primary end point was 4.50 events per 100 person-years in the placebo group, 4.11 events per 100 person-years in the 50-mg group, 3.86 events per 100 person-years in the 150-mg group, and 3.90 events per 100 person-years in the 300-mg group. The hazard ratios as compared with placebo were as follows: in the 50-mg group, 0.93 (95% confidence interval [CI], 0.80 to 1.07; P = 0.30); in the 150-mg group, 0.85 (95% CI, 0.74 to 0.98; P = 0.021); and in the 300-mg group, 0.86 (95% CI, 0.75 to 0.99; P = 0.031). The 150-mg dose, but not the other doses, met the prespecified multiplicity-adjusted threshold for statistical significance for the primary end point and the secondary end point that additionally included hospitalization for unstable angina that led to urgent revascularization (hazard ratio vs. placebo, 0.83; 95% CI, 0.73 to 0.95; P = 0.005). Canakinumab was associated with a higher incidence of fatal infection than was placebo. There was no significant difference in all-cause mortality (hazard ratio for all canakinumab doses vs. placebo, 0.94; 95% CI, 0.83 to 1.06; P = 0.31). Conclusions: Antiinflammatory therapy targeting the interleukin-1ÎČ innate immunity pathway with canakinumab at a dose of 150 mg every 3 months led to a significantly lower rate of recurrent cardiovascular events than placebo, independent of lipid-level lowering. (Funded by Novartis; CANTOS ClinicalTrials.gov number, NCT01327846.

    Mars: new insights and unresolved questions

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    Mars exploration motivates the search for extraterrestrial life, the development of space technologies, and the design of human missions and habitations. Here, we seek new insights and pose unresolved questions relating to the natural history of Mars, habitability, robotic and human exploration, planetary protection, and the impacts on human society. Key observations and findings include: – high escape rates of early Mars’ atmosphere, including loss of water, impact present-day habitability; – putative fossils on Mars will likely be ambiguous biomarkers for life; – microbial contamination resulting from human habitation is unavoidable; and – based on Mars’ current planetary protection category, robotic payload(s) should characterize the local martian environment for any life-forms prior to human habitation.Some of the outstanding questions are:– which interpretation of the hemispheric dichotomy of the planet is correct; – to what degree did deep-penetrating faults transport subsurface liquids to Mars’ surface; – in what abundance are carbonates formed by atmospheric processes; – what properties of martian meteorites could be used to constrain their source locations; – the origin(s) of organic macromolecules; – was/is Mars inhabited; – how can missions designed to uncover microbial activity in the subsurface eliminate potential false positives caused by microbial contaminants from Earth; – how can we ensure that humans and microbes form a stable and benign biosphere; and – should humans relate to putative extraterrestrial life from a biocentric viewpoint (preservation of all biology), or anthropocentric viewpoint of expanding habitation of space?Studies of Mars’ evolution can shed light on the habitability of extrasolar planets. In addition, Mars exploration can drive future policy developments and confirm (or put into question) the feasibility and/or extent of human habitability of space

    Science and Research

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    Astrobiology is one of the new multidisciplinary research fields of the 21st Century requiring collaborations across the physical sciences—astronomers, chemists, geologists, physicists—as well as people from the biosciences and, as discussed in this chapter, the humanities and social sciences. Astrobiology has a along and distinguished history in Europe though only in last decade has it develop its identity as a robust and independent field, one that will be further developed by new structures, such as the European Astrobiology Institute. This chapter looks at how astrobiology will develop in Europe and provide new career paths for next generation of researchers

    Fluid Flux in Fractured Rock of the Alpine Fault Hanging-Wall Determined from Temperature Logs in the DFDP-2B Borehole, New Zealand

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    ©2018. American Geophysical Union. All Rights Reserved. Sixteen temperature logs were acquired during breaks in drilling of the 893m-deep DFDP-2B borehole, which is in the Alpine Fault hanging-wall. The logs record various states of temperature recovery after thermal disturbances induced by mud circulation. The long-wavelength temperature signal in each log was estimated using a sixth-order polynomial, and residual (reduced) temperature logs were analyzed by fitting discrete template wavelets defined by depth, amplitude, and width parameters. Almost two hundred wavelets are correlated between multiple logs. Anomalies generally have amplitudes <1°C, and downhole widths <20m. The largest amplitudes are found in the first day after mud circulation stops, but many anomalies persist with similar amplitude for up to 15 days. Our models show that thermal and hydraulic diffusive processes are dominant during the first few days of re-equilibration after mud circulation stops, and fluid advection of heat in the surrounding rock produces temperature anomalies that may persist for several weeks. Models indicate that the fluid flux normal to the borehole within fractured zones is of order 10−7 to 10−6 m s−1, which is 2–3 orders of magnitude higher than the regional flux. Our approach could be applied more widely to boreholes, as it uses the thermal re-equilibration phase to derive useful information about the surrounding rock mass and its fluid flow regime

    Impact of high‐altitude therapy on type‐2 immune responses in asthma patients

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    Background Asthma patients present with distinct immunological profiles, with a predominance of type 2 endotype. The aim of this study was to investigate the impact of high‐altitude treatment on the clinical and immunological response in asthma. Methods Twenty‐six hospitalized asthma patients (nine eosinophilic allergic; EA, nine noneosinophilic allergic; NEA and eight noneosinophilic nonallergic; NN) and nine healthy controls in high altitude for 21 days were enrolled in the study. We assessed eosinophils, T cells, Tregs, and innate lymphoid cells (ILC) from peripheral blood using flow cytometry. Results The number of eosinophils (both resting and activated) and chemoattractant receptor homolog expressed on Th2 cells (CRTH2)‐expressing CD4+ and CD8+ T cells decreased significantly in EA patients after altitude treatment. The frequency of CRTH2+ Tregs as decreased significantly in all the asthma phenotypes as well as the frequency of ILC2 was significantly reduced in EA after altitude treatment. After 21 days of altitude therapy, CRTH2‐expressing ILC2, CD4+ and CD8+ T cells and Treg cells showed attenuated responses to exogenous PGD2. Furthermore, PGD2 signaling via CRTH2 was found to diminish the suppressive function of CRTH2+ Tregs which partially normalized during high‐altitude treatment. Improved asthma control was particularly evident in allergic asthma patients and correlated with decreased frequencies of CRTH2+ Treg cells in EA patients. Serum IL‐5 and IL‐13 decreased during climate treatment in asthma patients with high baseline levels. Conclusions Asthma treatment in high altitude reduced the type 2 immune response, corrected the increased CRTH2 expression and its dysregulated functions
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