Miracle-dz/UniFAR-FTUs huggingface dataset:
Origin of josephinite.

(BIRD and WEATHERS, 1975a). Although most samples of josephinite are somewhat altered, least-altered josephinite consists of several nickel-iron alloys, one intergrown with andradite garnet, an iron-cobalt alloy, and minor amounts of iron-nickel arsenides, iron-nickel-copper sulphides, and various unidentified phases. The intergrown metal-garent assemblage is apparently unique to josephinite. Alteration phases include serpentine minerals and magnetite. Josephinite occurs as detritus in several streams that originate and flow on the Josephine Peridotite; bedrock includes sheared serpentinite zones and basaltic to dioritic dikes within the peridotite. It is a reasonable assumption that the josephinite pebbles must be associated with one or more of these rocks; however, no unequivocal, large josephinite samples have been found within bedrock. BIRD and WEATHERS (1975a) proposed that because of its remarkable and apparently unique com position and textures, and its association with obducted mantle, josephinite has been derived from the mantle, conceivably the deep-mantle. Subsequently, DICK (1974), THORNBER and HAGGERTY (1976) and BOTTO and MORRISON (1976), following RAMDOHR (1950), argued that josephinite was formed by reduc tion of silicates, or sulphides, during serpentinization of the Josephine Peridotite. Currently, there are two views concerning the origin of josephinite: 1) josephinite is a product of low-temperature, syn serpentinization processes and is comparable with awaruite 2) because of its mineral composition, textures, and rock associations, josephinite pre-dated serpentinization of the Josephine Peridotite (obducted ophiolite), was related to the origin of the Josephine Peridotite, and was derived from the primitive mantle, conceivably from as deep as the core-mantle boundary. Excesses of 3He, 21Ne and 129Xe have recently been found in josephinite and have been interpreted to indicate a mantle residence and, perhaps, a primordial age for this rock (DOWNING et al., 1977; BOCHSLER et al., 1978). We continue to propose a mantle derivation of josephinite; additionally, we suggest that josephinite was primitive material in corporated into the earth during earth accretion.
Formulation of capillary hysteresis with internal state variables

A thermodynamically consistent framework is proposed for modeling the hysteresis of capillarity in partially saturated porous media. Capillary hysteresis is viewed as an intrinsic dissipation mechanism, which can be characterized by a set of internal state variables. The volume fractions of pore fluids are assumed to be additively decomposed into a reversible part and an irreversible part. The irreversible part of the volumetric moisture content is introduced as one of the internal variables. It is shown that the pumping effect occurring in a porous medium experiencing a wetting/drying cycle is thermodynamically admissible. A generic evolution equation for internal variables is developed. By virtue of the notion of the bounding surface plasticity, a model of capillary hysteresis is developed, which is capable of predicting all types of (primary, secondary, and higher‐order) scanning curves within the boundary loop. Provided that the main wetting curve and the main drying curve have been experimentally determined, the proposed model requires only one additional parameter to describe all the scanning curves. The model predictions are compared with experimental measurements found in the literature, showing that the new model is capable of describing the capillary hysteretic phenomena in a variety of partially saturated porous materials.
Sea surface pCO2‐SST relationships across a cold‐core cyclonic eddy: Implications for understanding regional variability and air‐sea gas exchange

This study is designed to improve the understanding of how biologically productive, cold‐core cyclonic eddies affect sea surface pCO2 in the lee of the main Hawaiian Islands in the subtropical North Pacific Gyre. We identified three unique relationships between pCO2 and sea surface temperature (SST). A positive correlation between pCO2 and SST was observed in the waters surrounding the eddy suggesting surface CO2 is controlled primarily by thermodynamics. In contrast, a negative relationship was observed within the eddy core as a result of the upwelling of CO2‐enriched subsurface waters. A third relationship existed throughout the rest of the eddy with reduced pCO2 suggesting a combination of biological uptake, physical upwelling and thermodynamic controls. In the absence of an eddy, this region is a CO2 sink, with the passage of the cold‐core mesoscale eddy decreasing the magnitude of the sink by ∼17%. However, if the general temperature correlation is used to predict pCO2 inside the cold eddy, it would overestimate the CO2 sink inside the eddy by 100%.
Trends in Monthly Temperature and Precipitation Extremes in the Zhujiang River Basin, South China (1961–2007)

Monthly temperature and precipitation time-series for the Zhujiang River Basin are analyzed in order to identify changes in climate extremes. Daily temperature and precipitation data from 1961 to 2007 of 192 meteorological stations are used. Two temperature indicators (monthly mean and monthly maximum mean) and three precipitation indicators (monthly total, monthly maximum consecutive 5-day precipitation, and monthly dry days) are analyzed. Tendencies in all five indicators can be observed. Many stations show significant positive trends (above the 90% confidence level) for monthly mean temperatures and monthly maximum mean temperatures. For all months, a significant increase in temperature from 1961 to 2007 can be observed in the entire basin with the coastal area in particular. Positive trends of precipitation extremes can be observed from January to March. Negative trends are detected from September to November. The number of dry days in October increased significantly at 40% of all meteorological stations. Stations with changes of monthly precipitation extremes are scattered over the Zhujiang River Basin. An aggregation of heat waves and droughts can be detected which is accompanied by significant increases of temperature extremes and the negative tendencies in precipitation extremes. The detection of tendencies in climate extremes essentially relies on a good data quality and high station density.
The relationship between sea surface temperature and chlorophyll-a concentration in fisheries aggregation area in the archipelagic waters of spermonde using satellite images

Analysis of relationship between sea surface temperature (SST) and chlorophyll-a (chl-a) increases our understanding on the productivity of the ocean. Satellite images provide reliable important information on oceanographic conditions and simultaneously support marine environmental monitoring and assessment. Monthly images of Moderate Resolution Imaging Spectroradiometer satellite (MODIS-Aqua) derived chl-a and SST from July 2002 to June 2011 around archipelagic waters of Spermonde Indonesia were used to investigate the relationship between SST and chl-a. While the daily data were used to produce the potential fishing ground maps of Rastrelliger kanagurta at the study area. Climatological images showed that the SST during the Southeast monsoon is lower thanthe Northwest monsoon, while chl-a during the Southeast monsoon is higher than the Northwest monsoonand isscattered along the coast. SST and chl-a showed an inverse correlation, with coefficient of correlation at R = 0.542. Preferred range of R. kanagurta were 30.75 ± 0.21°C for SST and 0.31 ± 0.10 mg m−3 for chl-a. Potential fishing grounds were found located around the coast. This study indicates that satellite image is able to determine the relationship between SST and chl-a and identify aggregation grounds of R. kanagurta.
Greenschist-facies metamorphism of the Burgess Shale and its implications for models of fossil formation and preservation

Metamorphosed silty mudstones of the Burgess Shale and Stephen Shale formations record a poly metamorphic history. An early greenschist-facies event associated with burial by Paleozoic strata produced a nearly ubiquitous bedding-parallel cleavage (S1). Tectonic exhumation during the formation of the southern Canadian Rocky Mountains produced a domainal subgreenschist-facies retrograde overprint in which a high-angle crenulation cleavage (S2) was developed. Whereas all rocks have experienced these two events, the degree of deformation and fossil pre servation varies with position relative to the Cathedral Escarpment. This paleosubmarine cliff resulted in a zone of reduced deformation within adjacent strata by buttressing them during burial and deflecting deformation during orogenesis. Fossil-bearing strata are composed of a typical greenschist assemblage of muscovitechloritequartzalbite, are devoid of clays, and contain an average of 0.28% organic carbon. This typical metamudstone assemblage is consiste.
Small‐scale, field‐aligned currents at the top‐side ionosphere

High‐precision vector magnetic field observations from the Ørsted satellite are used to investigate small‐scale, field‐aligned currents on spatial scales down to 600 m. Placed in a low‐Earth, polar orbit, the slowly drifting orbit plane has covered all local times since launch in 1999 with more than 25000 polar passes. Small‐scale currents are primarily found in the cusp with densities of 10–100 μAm−2, reaching more than 1000 μAm−2 during disturbed conditions. These values are 1–2 orders of magnitude larger than large‐scale region 1 and 2 currents. Current densities are 2–4 times larger when the ionosphere is illuminated than when in darkness. While the location of currents follows the changes in cusp location with changing IMF, the intensity of the currents seems to depend on the level of solar wind turbulence. The data suggest that small‐scale currents may be associated with significant local heating of the ionosphere and thermosphere.
Spatial fields of Antarctic sea-ice concentration anomalies for summer–autumn and their relationship to Southern Hemisphere atmospheric circulation during the period 1979–2009

Abstract Summer–autumn monthly sea-ice concentration anomaly (SICA) fields in Antarctica obtained from satellite data for the period 1979–2009 were analysed with Varimax-rotated T-mode principal component analysis (PCA). the first three PCA scores described the SICA spatial behaviour and explained 38.07% of the total variance. the related atmospheric circulation characteristics were analysed using 850 hPa height and surface air-temperature anomalies for the months clustered by the corresponding SICA composites, which were based on PCA loadings above a ±0.3 threshold. the principal characteristics of SICA can be seen between the Ross and Weddell Seas, areas that remained ice-covered during the analysis period. Elsewhere around Antarctica, small distinct characteristics occur mostly in embayments. the leading summer–autumn SICA pattern shows a structure with two centres of equal sign located one over the Weddell and the other over the Ross Sea–southwest Pacific Ocean sector and a centre of opposite sign over the Bellingshausen and Amundsen Seas. the second SICA pattern is represented by a dipole over the Weddell Sea as a result of an increase (decrease) in sea-ice concentration in the northern sector (positive phase) and a decrease (increase) in the southern region, together with a positive (negative) centre over the Ross and Amundsen Seas. the latter pattern is characterized by equal-sign anomalies on both sides of the Antarctic Peninsula and opposite-sign centres all around Antarctica with the highest intensity over the Ross Sea.
Retrieval of the aerosol size distribution from spectroradiometer measurements at a coastal site in the Mediterranean Sea

Values of aerosol optical depth,tau a lambda, have been obtained from spectral irradiance measurements registered at Valencia (Spain) between July 1993 and June 1995. Aerosol size distribution functions were calculated by considering these tau a lambda values and by using the inversion method proposed by King. The results show that such functions are bimodal, with a primary mode that is not apparent and a clearly defined secondary mode in the range 0.5-0.8mu m. Generally, the shape of the distribution function does not depend on the complex refractive index m assigned to the aerosols, although an increase in the imaginary part of m produces a decrease in the function's minimum.
The impact of El Niño–southern oscillation upon weather regimes over Europe and the North Atlantic during boreal winter

The influence of the warm and cold sea‐surface temperatures in the eastern and central equatorial Pacific associated with El Niño–southern oscillation (ENSO) on the probability of occurrence of weather regimes (WRs) over the North Atlantic sector is investigated for the period November–March. Five WRs are identified from daily sea‐level pressure anomalies (SLPAs) during 119 winters (1882–2000) over this sector by applying cluster analysis: the positive North Atlantic oscillation (NAO; called ZO for zonal) and negative NAO (called WBL for west blocking) patterns; GA (for Greenland anticyclone), with a positive SLPA shifted north of 60° N; EA (for European anticyclone) with a positive SLPA over Europe but enhanced north–south SLPA gradient over the western and central North Atlantic; and AR (for Atlantic Ridge) with a positive (negative) SLPA over the central North Atlantic (northern and central Europe).
Chapter 6 Regional stratigraphic correlations across the Aeolian archipelago (southern Italy)

Abstract A regional framework for stratigraphic correlations in the Aeolian archipelago is provided by widespread tephra layers and Late Quaternary marine terrace deposits combined with the available radiometric ages. Several tephra layers of Campanian and Aeolian provenance extending back to c. 110 ka are reported. The most important key-beds are the Ischia Tephra (56 ka), the Grey Porri Tuffs (70–67 ka) and Lower Pollara products (27.5 ka) from Salina, the M. Guardia pyroclastics from Lipari (27–24 ka) and the Brown Tuffs from Vulcano (c.70–8 ka). Late Quaternary marine terrace deposits are recognized along the coastal slopes of most of the Aeolian archipelago. They record distinct interglacial sea-level peaks during marine isotope stages (MIS) 5 and 7 in a context of prevalent long-term crustal uplift. Key erosional unconformities bounding the terrace deposits are the F1, UI, L3 and UII (in stratigraphic order). They are the ravinement surfaces formed at the onset of MIS 7.3 (F1), MIS 5e (UI) and MIS 5c interglacial peaks (L3), and the subaerial unconformity formed during the MIS 5a sea-level fall up to the emplacement of Brown Tuffs (UII). These unconformities are important regional-scale markers for chronostratigraphic classification and correlation between distant islands of the Aeolian archipelago.
Anomalous clastic wedge development during the Sevier-Laramide transition, North American Cordilleran foreland basin, USA

New, high-resolution, regional correlation and isopach maps provide evidence that (1) Laramide-style deformation began as early as ca. 77 Ma in central Utah, and (2) rapid (208 km m.y. –1 ) and extensive (400 km) progradation of a clastic wedge was facilitated by reduced subsidence during the transition from Sevier- to Laramide-style deformation. This study defi nes three Campanian, alluvialto-marine clastic wedges that traversed 200– 400 km eastward across the Utah-Colorado segment of the Cordilleran foreland basin. Wedges A and C are thicker successions with rising-trajectory shoreline stacking patterns (Blackhawk Formation and Lower Castlegate Sandstone, Bluecastle Tongue and Rollins Sandstone) that refl ect relatively slow overall progradation (50–81 km m.y. –1 ) of narrow (10–20 km wide), wave-dominated shorelines. In contrast, wedge B consists of lower-volume successions with a fl at to falling shoreline stacking pattern (Middle Castlegate Sandstone, Sego Sandstone, Neslen Formation, Corcoran and Cozzette Members of the Iles Formation) that suggests rapid progradation (~208 km m.y. –1 ) of embayed (60–80 km wide), mixed-energy (wave- and tide-infl uenced ) shore lines. Wedges A and C prograded 200–250 km in more than ~3 m.y. , whereas wedge B prograded 340–400 km in ~2 m.y. (~170 km m.y. –1 ). The anomalously extensive wedge B is unique in the Utah-Colorado segment because of its long extent, rapid progradation rate, dominance of tidally infl uenced facies, long-transit transgressions/regressions, and low-accommodation, nested sequence architecture. Stratigraphic relationships indicate development of wedge B coeval with both Sevier- and Laramide-style deformation in Utah. Assuming a constant sediment supply, the extensive (>300–400 km) “sheet-like” amalgamated wedge (wedge B) may have been caused by (1) reduced subsidence driven by a fl exural interference pattern, whereby two short-wavelength (±200 km) fl exural profi les are superimposed during the uplift of both basement-cored and thin-skinned thrust belt, (2) an increase in, or eastward migration of, dynamic subsidence during tectonic transitions associated with slab fl attening or rollback (i.e., long-wavelength fl exure), or (3) reduced subsidence due to short-wavelength fl exural interference augmented by the reduction, or migration, of long-wavelength fl
Comparison of the performance of flow‐routing algorithms used in GIS‐based hydrologic analysis

Flow direction and specific catchment area were calculated for different flow‐routing algorithms using TAPES‐G and TauDEM. A fuzzy classification was used along with eight topo–climatic attributes to delineate six landscape classes from a 10‐m USGS DEM. A series of maps and tabular outputs were produced to compare flow‐routing predictions in different parts of the study area in the Santa Monica Mountains of southern California. The matched pair t‐test was used to compare the performance of pairs of specific catchment area grids across six user‐defined fuzzy landscape classes. The results show that (1) the ‘source’ cells predicted with the D∞, DEMON, and FD8 algorithms were confined to hilltops; (2) two single flow‐routing algorithms (Rho8, D8) produced poor results; and (3) the choice of flow‐routing algorithm has potentially important consequences for the calculation of upslope contributing areas, sediment transport capacity, topographic wetness, and several other topographic indices. Copyright © 2007 John Wiley & Sons, Ltd.
Extending records of the isotopic composition of atmospheric N2O back to 1800 A.D. from air trapped in snow at the South Pole and the Greenland Ice Sheet Project II ice core

A historical record of changes in the N2O isotope composition is important for a better understanding of the biogeochemical cycles involving atmospheric N2O. Here we combine measurements of trapped gases in the Greenland Ice Sheet Project II (GISP II) ice core and the interstitial air from the snowpack at the South Pole to reconstruct atmospheric N2O isotope records back to 1785 A.D. Results from six measurements of ice with gas ages between 1785 and 1819 A.D. indicate that the δ15N and δ18O of atmospheric N2O was 10.1 ± 0.6 and 47.4 ± 1.0‰, respectively. These values are 1.9 and 2.9‰ higher than present‐day values as measured in this study. A simple two‐box atmospheric model was constructed to simulate the various sources and sinks of atmospheric N2O over the last 250 years. Model results suggest that the total anthropogenic N2O emissions in 1995 were between 4.2 and 5.7 Tg N yr−1. The ice core and box model results were compared to δ15N and δ18O measurements of air trapped in the snowpack at South Pole spanning the 20th century. Our results suggest that δ15N and δ18O of atmospheric N2O have dropped by 1.7 and 0.9‰, respectively, during the last century. These data support previous predictions of decreasing atmospheric isotope ratios that are related to a ∼30% increase in total N2O emissions which are primarily related to agricultural activities.
Modelling of short-interval silent slip events in deeper subduction interfaces considering the frictional properties at the unstable-stable transition regime

SUMMARY Recent high-resolution observations of crustal movements have revealed silent slip events (SSEs) with propagation velocities of around 10–15 km d−1 and with intervals of 3–14 months along the deeper parts of the Cascadia and Nankai subduction zones. This study develops 2-D and 3-D models of these short-interval SSEs considering the frictional behaviour that was confirmed experimentally by Shimamoto for the unstable–stable transition regime. To represent this frictional behaviour, a small cut-off velocity to an evolution effect is introduced in a rate- and state-dependent friction law. When the cut-off velocity to the evolution effect is significantly smaller than that to a direct effect, steady-state friction exhibits velocity weakening at low slip velocities and velocity strengthening at high slip velocities. At the deeper Cascadia and Nankai subduction interfaces, the pore pressure is inferred to be high because of the dehydration of materials in the descending plate. Under conditions where the pore-fluid pressure is nearly equal to the lithostatic pressure and the critical weakening displacement is very small, short-interval SSEs with propagation velocities and slip velocities of 4–8 km d−1 and 2 − 4 × 10−7 m s−1, respectively, can be reproduced. The propagation velocity of short-interval SSEs is in proportion to the slip velocity. The results also show that during the nucleation process of large earthquakes, the occurrence of short-interval SSEs becomes irregular because of the accelerated slips that occur at the bottom of the seismogenic zone. Our results suggest that monitoring of short-interval SSEs might be useful for forecasting the main earthquakes.
Precise temperature estimation in the Tibetan crust from seismic detection of the α-β quartz transition

In the deep crust, temperature, which is among the key pa- rameters controlling lithospheric dynamics, is inferred by extrap- olation from the surface using several assumptions that may fail in regions of active tectonics and fluid migration. In the rare case that temperatures of 700 8C or higher are exceeded in the upper and middle continental crust composed of quartz-rich felsic rocks, the a-b quartz transition (ABQT) will occur, generating a mea- surable seismic signature and offering the possibility for precisely estimating temperature from the known ABQT phase diagram. Here it is shown that all expected seismic features of the ABQT are met by the boundary between the upper and middle crust be- low the INDEPTH III profile in central Tibet. This finding implies that a temperature of 700 8C is achieved at a depth of 18 km under the southern Qiangtang block, which agrees with the depth to the top of a high electrical conductivity anomaly, likely representing partially melted crust. To the south in the northern Lhasa block, the ABQT is at 32 km depth, corresponding to a temperature of 800 8C. It thus appears that this seismic boundary representing the ABQT is the result of recent geologic processes rather than being a lithologic boundary.
Stochastic resonance in the North Atlantic

Large, abrupt changes between warm and cold modes of North Atlantic climate exhibit spectral power at ∼1500 years, yet some climatic changes were linked to outburst floods and other events that are unlikely to have been truly periodic. We hypothesize that a weak periodic forcing has combined with “noise” from ice sheet-related events to cause the observed mode switches. This stochastic resonance hypothesis predicts a recurrence pattern between warmings that is distinct from the predictions of simple periodic and stochastic models and at least some other models. The ice isotopic data from central Greenland ice cores are consistent with the stochastic resonance hypothesis but not with other models we have tested. We thus support arguments for the existence of a periodicity of ∼1500 years in the North Atlantic climate system and for the importance of ice sheet events in forcing North Atlantic changes.