Constraints on fault and lithosphere rheology from the coseismic slip and postseismic afterslip of the 2006 M_w 7.0 Mozambique earthquake

The 2006 M_w 7.0 Mozambique (Machaze) normal-faulting earthquake ruptured an unusually steeply dipping fault plane (~75°). The amount of slip in the earthquake decreased from depths of ~10 km toward the surface, and this shallow slip deficit was at least partly recovered by postseismic afterslip on the shallow part of the fault plane. An adjacent normal fault segment slipped postseismically (and possibly also co-seismically) at shallow depths with a large strike-slip component, in response to the stresses generated by slip on the main earthquake fault plane. Our observations suggest that the fault zone behaves in a stick-slip manner in the crystalline basement, and that where it cuts the sedimentary layer the coseismic rupture was partially arrested and there was significant postseismic creep. We discuss the effects of such behavior on the large-scale tectonics of continental regions, and on the assessment of seismic hazard on similar fault systems. The steep dip of the fault suggests the re-activation of a preexisting structure with a coefficient of friction at least ~25–45% lower than that on optimally oriented planes, and analysis of the deformation following an aftershock indicates that the value of the parameter ‘a’ that describes the rate-dependence of fault friction lies in the range 1 × 10^(−3)–2 × 10^(−2). The lack of long-wavelength postseismic relaxation suggests viscosities in the ductile lithosphere of greater than ~2 × 10^(19) Pa s, and an examination of the tectonic geomorphology in the region identifies ways in which similar fault systems can be identified before they rupture in future earthquakes

The 2001 M_w 7.6 Bhuj earthquake, low fault friction, and the crustal support of plate driving forces in India

We present a source model for the 2001 M_w 7.6 Bhuj earthquake of northwest India. The slip distribution suggests a high stress drop (~35 MPa) and, together with the depth distribution of aftershocks, that the entire crust is seismogenic. We suggest that the active faults have an effective coefficient of friction of ~0.08, which is sufficient for the seismogenic crust to support the majority of the compressive force transmitted through the Indian lithosphere. This model is consistent with the midcrustal depth of the transition from extension to compression beneath the Ganges foreland basin where India underthrusts southern Tibet. If the coefficient of friction were the more traditional value of 0.6, the lithosphere would be required to support a net force roughly an order of magnitude higher than current estimates in order to match the observed depth of the neutral fiber

Subparallel thrust and normal faulting in Albania and the roles of gravitational potential energy and rheology contrasts in mountain belts

The active tectonics of Albania and surrounding regions, on the eastern margin of the Adriatic Sea, is characterized by subparallel thrust and normal faulting which, we suggest, is likely to be related to gravitational potential energy contrasts between the low-lying Adriatic Sea and the elevated mountainous areas inland. We calculate the magnitude of the force which the mountains and lowlands exert upon each other as a result of this potential energy contrast. It is likely that this force is largely supported by shear stresses on faults, and if so, the average stresses are less than ∼20 MPa. Alternatively, if the mountains are supported by stresses in the ductile part of the lithosphere, the stresses are likely to be ∼80–240 MPa in magnitude. The mountains of Albania are significantly lower than other ranges, such as the Peruvian Andes, which are thought to be extending in response to potential energy differences, and we discuss the relation between Albania and these other, higher, mountain belts from the perspective of differences in lithosphere rheology. We suggest that the lowlands of western Albania and the Adriatic Sea may have been weakened through time as a result of the deposition of large thicknesses of sediment, which lead to heating of the crystalline basement, a reduction in the potential energy contrast that could be supported by the lowlands, and so normal faulting in the mountains of eastern Albania

External Impacts of Local Energy Policy: The Case of Renewable Portfolio Standards

Renewable portfolio standards (RPSs) are state level policies that require in-state electricity providers to procure a minimum percentage of electricity sales from renewable sources. Using theoretical and empirical models, we show how RPSs induce out-of-state emissions reductions through inter-state trade of the credits used for RPS compliance. When one state passes an RPS, it increases demand for credits sold by firms in other (potentially non-RPS) states. We find evidence that increasing a state’s RPS decreases coal generation and increases wind generation in outside states through this tradable credit channel. We perform a welfare simulation to evaluate the aggregate benefits of the reductions in local coal-fired pollutants induced by RPSs. Our estimates suggest that a 1 percentage point increase a state’s RPS results in up to $100 million in gross benefits towards the United States as a whole. However, there is substantial heterogeneity in the total benefits caused by increases in different states’ RPSs

Oroclinal bending, distributed thrust and strike-slip faulting, and the accommodation of Arabia–Eurasia convergence in NE Iran since the Oligocene

Regional shortening is accommodated across NE Iran in response to the collision of Arabia with Eurasia. We examine how N–S shortening is achieved on major thrust systems bounding the eastern branch of the Alborz (east of 57°E), Sabzevar and Kuh-e-Sorkh mountain ranges, which lie south of the Kopeh Dagh mountains in NE Iran. Although these ranges have experienced relatively few large earthquakes over the last 50 yr, they have been subject to a number of devastating historical events at Neyshabur, Esfarayen and Sabzevar. A significant change in the tectonics of the eastern Alborz occurs directly south of the Central Kopeh Dagh, near 57°E. To the east, shortening occurs on major thrust faults which bound the southern margin of the range, resulting in significant crustal thickening, and forming peaks up to 3000 m high. Active shortening dies out eastward into Afghanistan, which is thought to belong to stable Eurasia. The rate of shortening across thrust faults bounding the south side of the eastern Alborz north of Neyshabur is determined using optically stimulated luminescence dating of displaced river deposits, and is likely to be 0.4–1.7 mm yr^(−1). Shortening across the Sabzevar range 150 km west of Neyshabur has previously been determined at 0.4–0.6 mm yr^(−1), although reassessment of the rate here suggests it may be as high as 1 mm yr^(−1). Migration of thrust faulting into foreland basins is common across NE Iran, especially in the Esfarayen region near 57°E, where the northward deflection of the East Alborz range reaches a maximum of 200 ± 20 km (from its presumed linear E–W strike at the beginning of the Oligocene). West of 57°E, the tectonics of the Alborz are affected by the westward motion of the South Caspian region, which results in the partitioning of shortening onto separate thrust and left-lateral strike-slip faults north and south of the range. At the longitude of 59°E, published GPS velocities indicate that 50 per cent of the overall shortening across NE Iran is accommodated in the Kopeh Dagh. The remaining 50 per cent regional shortening must therefore be accommodated south of the Kopeh Dagh, in the eastern Alborz and Kuh-e-Sorkh ranges. Assuming present day rates of slip and the fault kinematics are representative of the Late Cenozoic deformation in NE Iran, the total 200 ± 20 km N–S shortening across the eastern Alborz and Kopeh Dagh mountains since the beginning of uplift of the Kopeh Dagh basin would be accommodated in 30 ± 8 Ma. Although this extrapolation may be inappropriate over such a long timescale, the age is nevertheless consistent with geological estimates of post Early-to-Middle Oligocene (<30 Ma) for the onset of Kopeh Dagh uplift

Population genomics reveal deep divergence and strong geographical structure in gentians in the Hengduan Mountains

Understanding the evolutionary and ecological processes driving population differentiation and speciation can provide critical insights into the formation of biodiversity. Here, we examine the link between population genetic processes and biogeographic history underlying the generation of diversity in the Hengduan Mountains (HM), a region harboring a rich and dynamic flora. We used restriction site-associated DNA sequencing to generate 1,907 single-nucleotide polymorphisms (SNPs) and four-kb of plastid sequence in species of the Gentiana hexaphylla complex (Gentianaceae). We performed genetic clustering with spatial and non-spatial models, phylogenetic reconstructions, and ancestral range estimation, with the aim of addressing the processes influencing diversification of G. hexaphylla in the HM. We find the G. hexaphylla complex is characterized by geographic genetic structure with clusters corresponding to the South, North and the central HM. Phylogenetic reconstruction and pairwise F(ST) analyses showed deep differentiation between Southern and Northern populations in the HM. The population in Mount Taibai exhibited the highest genetic similarity to the North HM. Ancestral range estimation indicated that the G. hexaphylla complex originated in the central HM and then diverged in the Pliocene and the Early Pleistocene, before dispersing widely, resulting in the current distinct lineages. Overall, we found deep genomic differentiation in the G. hexaphylla complex corresponds to geographic barriers to dispersal in the HM and highlights a critical role of the uplift of the Daxue Mountains and subsequent climatic fluctuations underlying diversification. The colonization of G. hexaphylla in the Mount Taibai region suggests directional dispersal between the alpine flora of the Qinling Mountains and the HM

Targeted treatment of yaws with contact tracing : how much do we miss?

Yaws is a disabling bacterial infection found primarily in warm and humid tropical areas. The World Health Organization strategy mandates an initial round of total community treatment (TCT) with single-dose azithromycin followed either by further TCT or active case-finding and treatment of cases and their contacts (the Morges strategy). We sought to investigate the effectiveness of the Morges strategy. We employed a stochastic household model to study the transmission of infection using data collected from a pre-TCT survey conducted in the Solomon Islands. We used this model to assess the proportion of asymptomatic infections that occurred in households without active cases. This analysis indicated that targeted treatment of cases and their household contacts would miss a large fraction of asymptomatic infections (65%–100%). This fraction was actually higher at lower prevalences. Even assuming that all active cases and their households were successfully treated, our analysis demonstrated that at all prevalences present in the data set, up to 90% of (active and asymptomatic) infections would not be treated under household-based contact tracing. Mapping was undertaken as part of the study “Epidemiology of Yaws in the Solomon Islands and the Impact of a Trachoma Control Programme,” in September–October 2013

Targeted Treatment of Yaws With Household Contact Tracing: How Much Do We Miss?

Yaws is a disabling bacterial infection found primarily in warm and humid tropical areas. The World Health Organization strategy mandates an initial round of total community treatment (TCT) with single-dose azithromycin followed either by further TCT or active case-finding and treatment of cases and their contacts (the Morges strategy). We sought to investigate the effectiveness of the Morges strategy. We employed a stochastic household model to study the transmission of infection using data collected from a pre-TCT survey conducted in the Solomon Islands. We used this model to assess the proportion of asymptomatic infections that occurred in households without active cases. This analysis indicated that targeted treatment of cases and their household contacts would miss a large fraction of asymptomatic infections (65%-100%). This fraction was actually higher at lower prevalences. Even assuming that all active cases and their households were successfully treated, our analysis demonstrated that at all prevalences present in the data set, up to 90% of (active and asymptomatic) infections would not be treated under household-based contact tracing. Mapping was undertaken as part of the study "Epidemiology of Yaws in the Solomon Islands and the Impact of a Trachoma Control Programme," in September-October 2013

Time course of normalization of functional β-cell capacity in the Diabetes Remission Clinical Trial after weight loss in type 2 diabetes

Objective: To assess functional β-cell capacity in type 2 diabetes during 2 years of remission induced by dietary weight loss. Research Design and Methods: A Stepped Insulin Secretion Test with Arginine was used to quantify functional β-cell capacity by hyperglycemia and arginine stimulation. Thirty-nine of 57 participants initially achieved remission (HbA1c &lt;6.5% [&lt;48 mmol/mol] and fasting plasma glucose &lt;7 mmol/L on no antidiabetic drug therapy) with a 16.4 ± 7.7 kg weight loss and were followed up with supportive advice on avoidance of weight regain. At 2 years, 20 participants remained in remission in the study. A nondiabetic control (NDC) group, matched for age, sex, and weight after weight loss with the intervention group, was studied once. Results: During remission, median (interquartile range) maximal rate of insulin secretion increased from 581 (480–811) pmol/min/m2 at baseline to 736 (542–998) pmol/min/m2 at 5 months, 942 (565–1,240) pmol/min/m2 at 12 months (P = 0.028 from baseline), and 936 (635–1,435) pmol/min/m2 at 24 months (P = 0.023 from baseline; n = 20 of 39 of those initially in remission). This was comparable to the NDC group (1,016 [857–1,507] pmol/min/m2) by 12 (P = 0.064) and 24 (P = 0.244) months. Median first-phase insulin response increased from baseline to 5 months (42 [4–67] to 107 [59–163] pmol/min/m2; P &lt; 0.0001) and then remained stable at 12 and 24 months (110 [59–201] and 125 [65–166] pmol/min/m2, respectively; P &lt; 0.0001 vs. baseline) but lower than that of the NDC group (250 [226–429] pmol/min/m2; P &lt; 0.0001). Conclusions: A gradual increase in assessed functional β-cell capacity occurred after weight loss, becoming similar to NDC participants by 12 months. This was unchanged at 2 years with continuing remission of type 2 diabetes

Inhibitor development in non-severe haemophilia across Europe

Evidence about inhibitor formation in non-severe haemophilia and the potential role for clotting factor concentrate type is scant. It was the aim of this study to report inhibitor development in non-severe haemophilia patients enrolled in the European Haemophilia Safety Surveillance (EUHASS) study. Inhibitors are reported quarterly and total treated patients annually. Incidence rates and 95 % confidence intervals (95 % CI) were calculated according to diagnosis and concentrate used. Between 1–10–2008 and 31–12–2012, 68 centres reported on 7,969 patients with non-severe haemophilia A and 1,863 patients with non-severe haemophilia B. For haemophilia A, 37 inhibitors occurred in 8,622 treatment years, resulting in an inhibitor rate of 0.43/100 treatment years (95 % CI 0.30–0.59). Inhibitors occurred at a median age of 35 years, after a median of 38 exposure days (EDs; P25-P75: 20–80); with 72 % occurring within the first 50 EDs. In haemophilia B, one inhibitor was detected in 2,149 treatment years, resulting in an inhibitor rate of 0.05/100 years (95% CI 0.001–0.26). This inhibitor developed at the age of six years, after six EDs. The rate of inhibitors appeared similar across recombinant and plasma derived factor VIII (FVIII) concentrates. Rates for individual concentrates could not be calculated at this stage due to low number of events. In conclusion, inhibitors in non-severe haemophilia occur three times more frequently than in previously treated patients with severe haemophilia at a rate of 0.43/100 patient years (haemophilia A) and 0.05/100 years (haemophilia B). Although the majority of inhibitors developed in the first 50 EDs, inhibitor development continued with increasing exposure to FVIII