Miracle-dz/UniFAR-FTUs huggingface dataset:
Geologic correlation of the Himalayan orogen and Indian craton: Part 2. Structural geology, geochronology, and tectonic evolution of the Eastern Himalaya

Despite being the largest active collisional orogen on Earth, the growth mechanism of the Himalaya remains uncertain. Current debate has focused on the role of dynamic interaction between tectonics and climate and mass exchanges between the Himalayan and Tibetan crust during Cenozoic India-Asia collision. A major uncertainty in the debate comes from the lack of geologic information on the eastern segment of the Himalayas from 91°E to 97°E, which makes up about one-quarter of the mountain belt. To address this issue, we conducted detailed field mapping, U-Pb zircon age dating, and 40Ar/39Ar thermochronology along two geologic traverses at longitudes of 92°E and 94°E across the eastern Himalaya. Our dating indicates the region experienced magmatic events at 1745–1760 Ma, 825–878 Ma, 480–520 Ma, and 28–20 Ma. The first three events also occurred in the northeastern Indian craton, while the last is unique to the Himalaya. Correlation of magmatic events and age-equivalent lithologic units suggests that the eastern segment of the Himalaya was constructed in situ by basement-involved thrusting, which is inconsistent with the hypothesis of high-grade Himalaya rocks derived from Tibet via channel flow. The Main Central thrust in the eastern Himalaya forms the roof of a major thrust duplex; its northern part was initiated at ca. 13 Ma, while the southern part was initiated at ca. 10 Ma, as indicated by 40Ar/39Ar thermochronometry. Crustal thickening of the Main Central thrust hanging wall was expressed by discrete ductile thrusting between 12 Ma and 7 Ma, overlapping in time with motion on the Main Central thrust below. Restoration of two possible geologic cross sections from one of our geologic traverses, where one assumes the existence of pre-Cenozoic deformation below the Himalaya and the other assumes flat-lying strata prior to the India-Asia collision, leads to estimated shortening of 775 km (∼76% strain) and 515 km (∼70% strain), respectively. We favor the presence of significant basement topography below the eastern Himalaya based on projections of early Paleozoic structures from the Shillong Plateau (i.e., the Central Shillong thrust) located ∼50 km south of our study area. Since northeastern India and possibly the eastern Himalaya both experienced early Paleozoic contraction, the estimated shortening from this study may have resulted from a combined effect of early Paleozoic and Cenozoic deformation.
Offshore propagation of eddy kinetic energy in the California Current

Low-pass-filtered velocities obtained from surface drifters and surface geostrophic velocities estimated from TOPEX/Poseidon altimeter data have recently revealed a clear and robust seasonal cycle in the surface eddy kinetic energy (EKE) in the California Current (CC) [Kelly et al., 1998; Strub and James, 2000]. The seasonal cycle begins in spring when a surface-intensified baroclinic equatorward jet develops next to the coast in response to strong upwelling favorable winds. This jet, and a developing eddy field, then moves offshore during summer and fall. The EKE maximum associated with the jet progresses only as far as 127°W, beyond which it decreases rapidly. This is a robust characteristic of the seasonal cycle that has been previously attributed only to an unspecified dissipation process. To investigate this aspect of the surface EKE, a multiyear simulation of the CC is carried out using the Dietrich/Center for Air-Sea Technology primitive equation regional ocean model [Dietrich, 1997]. The simulation accurately reproduces many aspects of the observed annual cycle, including the offshore propagation of the EKE at the surface. The model results indicate that the decrease of surface EKE west of 127°W in the simulation is not due to dissipation but rather is caused by the vertical redistribution of EKE to the deep ocean. This redistribution occurs through the transformation of kinetic energy from the vertical shear flow to the vertical mean flow. The transformation is a nonlinear process inherently associated with the life cycle of baroclinically unstable waves, and in the CC, it effectively energizes the deeper ocean at the expense of the upper ocean. The process is also known to be important in the atmosphere [Wiin-Nielsen, 1962]. Taken together, the recent California Current observations and the new model results strongly suggest that the CC regularly supplies EKE to the deep waters of the eastern North Pacific.
Preliminary results on the Co, Sr and Cs sorption properties of the analcime-containing rock type of the Boda Siltstone Formation

Abstract The search for nuclear waste deposits have been focusing on formations containing large amounts of clay minerals, as they potentially possess significant isolation capacity due to their radionuclide sorption ability. In this study the immobilization processes for Co, Sr and Cs ions on the recently described analcime-containing rock type of the Boda Siltstone Formation were investigated by batch sorption experiments. Our data suggest a high radionuclide immobilization capacity for this rock formation in the following order: Sr > Co > Cs. The dominant immobilization processes were found to be ion exchange and precipitation for Co and Sr, and chemisorption for Cs. The necessity of further sorption analyses on the studied rock formation is also raised.
Altimetry of the Venus cloud tops from the Venus Express observations

[1] Simultaneous observations of Venus by Visible and Infrared Thermal Imaging Spectrometer and Venus Monitoring Camera onboard the Venus Express spacecraft are used to map the cloud top altitude and to relate it to the ultraviolet (UV) markings. The cloud top altitude is retrieved from the depth of CO2 absorption band at 1.6 μm. In low and middle latitudes the cloud top is located at 74 ± 1 km. It decreases poleward of ±50° and reaches 63–69 km in the polar regions. This depression coincides with the eye of the planetary vortex. At the same latitude and hour angle, cloud top can experience fast variations of about 1 km in tens of hours, while larger long-term variations of several kilometers have been observed only at high latitudes. UV markings correlate with the cloud altimetry, however, the difference between adjacent UV dark and bright regions does not exceed several hundred meters. Surprisingly, CO2 absorption bands are often weaker in the dark UV features, indicating that these clouds may be a few hundred meters higher or have a larger scale height than neighboring clouds. Ultraviolet dark spiral arms, which are often seen at about −70°, correspond to higher altitudes or to the regions with strong latitudinal gradient of the cloud top altitude. Cloud altimetry in the polar region reveals the structure that correlates with the thermal emission maps but is invisible in UV images. This implies that the UV optically thick polar hood is transparent in the near IR.
Links between bulk sediment particle size and magnetic grain‐size: general observations and implications for Chinese loess studies

Using a combination of particle size analysis, magnetic measurements, scanning electron microscopy and transmission electron microscopy imaging, this study shows that in a wide range of depositional environments, there is a strong link between particle size classes and magnetic response, especially below the upper limit of stable single domain magnetic behaviour. Ferrimagnetic grain assemblages dominated by stable single domain magnetosomes regularly have peak susceptibility and remanence values in coarser grades than do those containing finer‐grained, viscous and superparamagnetic secondary magnetic minerals formed during pedogenesis. This effect is despite the fact that there is a one to two orders of magnitude size difference between the particle size boundaries (at 1 or 2 μm) and key domain state transitions (mostly below 0·05 μm). The implications of these results are explored using samples spanning 22 Myr of loess accumulation on the Chinese Loess Plateau. The results from the loess sections, complemented by data from low‐temperature magnetic experiments, show that there are subtle distinctions in mean ferrimagnetic grain‐size between the Pleistocene and Miocene parts of the record, thus allowing more refined rock magnetic interpretations of the fine‐grained ferrimagnetic mineral assemblages arising from the effects of weathering, pedogenesis and possibly diagenesis in the sections studied.
RULE OF LAW , DEMOCRACY , OPENNESS , AND INCOME : ESTIMATING THE INTERRELATIONSHIPS 1

We estimate the interrelationships among economic institutions, political institutions, openness, and income levels, using identification through heteroskedasticity (IH). We split our cross-national dataset into two sub-samples: (i) colonies versus non-colonies; and (ii) continents aligned on an East-West versus those aligned on a North-South axis. We exploit the difference in the structural variances in these two sub-samples to gain identification. We find that democracy and the rule of law are both good for economic performance, but the latter has a much stronger impact on incomes. Openness (trade/GDP) has a negative impact on income levels and democracy, but a positive effect on rule of law. Higher income produces greater openness and better institutions, but these effects are not very strong. Rule of law and democracy tend to be mutually reinforcing. 1 We thank Vincent Hogan, Aart Kray and Ricardo Hausmann for very useful comments. We also thank the participants at the Macro Seminar at the World Bank for the comments and suggestions. All remaining errors are ours. RULE OF LAW, DEMOCRACY, OPENNESS, AND INCOME: ESTIMATING THE INTERRELATIONSHIPS Roberto Rigobon and Dani Rodrik
Bubbles between the wave trough and wave crest levels

In order to estimate ocean-atmosphere mass transfer fluxes controlled by aerosol generation the bubble population at the interface has to be known. This information is usually inferred from measurements at a given depth below the water surface and from broad assumptions about the variation of bubble population with depth. However, recent measurements are not consistent with the usually assumed bubble population variation, and a direct investigation in the immediate vicinity of the interface appears to be necessary. Measurements above the minimum wave trough are difficult because a sensor level is alternately in the air and in the water. We have used a laser-based single-particle technique to investigate this zone for different breaking wave fields generated in a wind-water simulation facility. The main bubble population characteristics, common to the different breaking wave fields investigated, are as follows: a roughly invariant size distribution characterized by a spectrum slope of approximately −2, concentrations rapidly increasing upward, following approximately an exponential law, and clustered distributions at the different measurement levels. These results, consistent with equivalent measurements below the wave trough level, correspond to bubble generation zone characteristics suggested in a previous investigation and provide further evidence of the existence of a universal bubble distribution at the interface of breaking wave fields. Very high bubble concentrations, up to 1010 bubbles of diameter larger than 60 μ per cubic meter (nearly 10,000-fold the value just below the trough level), are observed at the crest levels.
Ground and satellite observations of nighttime medium‐scale traveling ionospheric disturbance at midlatitude

[1] We have investigated a nighttime medium-scale traveling ionospheric disturbance (MSTID) observed by an airglow imager at Shigaraki (34.9°N, 25.4°MLAT), Japan, on 17 May 2001. The structure was identified in the airglow images of OI (630.0 nm and 777.4 nm) as NW-SE band structures (horizontal wavelength: 230 km) moving southwestward with a velocity of 50 m/s. Neutral wind velocity was measured simultaneously from the Doppler shift of the 630.0-nm emission by a Fabry-Perot interferometer at Shigaraki. From these parameters, we performed model calculations of MSTIDs generated by gravity waves and by an oscillating electric field. We found that for the case of gravity waves, the estimated vertical wavelength was too small to explain the observed amplitudes of airglow intensity. For the case of the electric field, we found that an electric field oscillation of ∼1.2 mV/m was sufficient to reproduce the observed airglow amplitudes. This modeled electric field was comparable to that observed by the DMSP F15 satellite as it passed over Shigaraki during our observing period on 17 May 2001. The DMSP ion drift data show that the oscillation of the polarization electric field correlated with the MSTID structure in the airglow image, suggesting that the polarization electric field plays an important role in the generation of MSTIDs.
Atmospheric correction for the monitoring of land surfaces

[1] This paper briefly describes the land surface reflectance product (MOD09), the current Moderate Resolution Imaging Spectroradiometer (MODIS) atmospheric correction (AC) algorithm and its recent updates, and provides the evaluation of the algorithm performance and product quality. The accuracy of the AC algorithm has been significantly improved owing to the use of the accurate Second Simulation of a Satellite Signal in the Solar Spectrum, Vector (6SV) radiative transfer code and a better retrieval of aerosol properties by a refined internal aerosol inversion algorithm. The Collection 5 MOD09 surface reflectance product computed by the improved AC algorithm was analyzed for the year of 2003 through the comparison with a reference data set created with the help of Aerosol Robotic Network (AERONET) measurements and the 6SV code simulations. In general, the MOD09 product demonstrated satisfactory quality in all used MODIS bands except for band 3 (470 nm), which is used for aerosol inversion. The impact of uncertainties in MOD09 upon the downstream product, such as vegetation indices and albedo, was also evaluated.
Many hands on this study: Development of a metonymy comprehension task

ABSTRACT Metonymy is a pervasive linguistic/cognitive mechanism in everyday language. Still, studies assessing its comprehension are rare in the literature. Our goal is to present the elaboration of a verbal metonymy comprehension task in Brazilian Portuguese as well as test it using pilot studies. The task was based on the cognitive linguistics framework and psychometric guidelines were considered. The construction of the task considered psycholinguistic variables and included a conventionality task and an expert analysis. Three studies (N = 290, ages ranging 2 to 54 years old) were conducted until we reached a final version. The study resulted in a task composed of one practice item and six test items. Each item includes a sentence-stimulus and two questions (one open-ended and one closed-ended). Together, the items make up a raw score that represents metonymy comprehension. Data obtained from the pilot studies show that metonymy comprehension improves gradually with age and that there is a significant difference between items in both types of questions. This is in consonance with the literature, and thus points towards the instrument’s construct validity. The study results in a task that presents enough sensitivity to gauge comprehension of this phenomenon at different ages.
Utilizing the Global Land Cover 2000 reference dataset for a comparative accuracy assessment of 1 km global land cover maps

Abstract. Many investigators use global land cover (GLC) maps for different purposes, such as an input for global climate models. The current GLC maps used for such purposes are based on different remote sensing data, methodologies and legends. Consequently, comparison of GLC maps is difficult and information about their relative utility is limited. The objective of this study is to analyse and compare the thematic accuracies of GLC maps (i.e., IGBP-DISCover, UMD, MODIS, GLC2000 and SYNMAP) at 1 km resolutions by (a) re-analysing the GLC2000 reference dataset, (b) applying a generalized GLC legend and (c) comparing their thematic accuracies at different homogeneity levels. The accuracy assessment was based on the GLC2000 reference dataset with 1253 samples that were visually interpreted. The legends of the GLC maps and the reference datasets were harmonized into 11 general land cover classes. There results show that the map accuracy estimates vary up to 10-16% depending on the homogeneity of the reference point (HRP) for all the GLC maps. An increase of the HRP resulted in higher overall accuracies but reduced accuracy confidence for the GLC maps due to less number of accountable samples. The overall accuracy of the SYNMAP was the highest at any HRP level followed by the GLC2000. The overall accuracies of the maps also varied by up to 10% depending on the definition of agreement between the reference and map categories in heterogeneous landscape. A careful consideration of heterogeneous landscape is therefore recommended for future accuracy assessments of land cover maps.
Mapping subtle structures with light detection and ranging (LIDAR): flow units and phreatomagmatic rootless cones in the North Mountain Basalt, Nova Scotia

Light detection and ranging (LIDAR) is an emerging technology to generate high-resolution digital elevation models (DEMs). Subtle topographical differences among three flow units of the Jurassic North Mountain Basalt, eastern Canada, are visible on a LIDAR-derived DEM. The boundaries were verified by field mapping and allow a simple projection of the contact planes through the terrain model to provide a three-dimensional visualization of the flow units. Several ring structures in the lower flow unit, distinguishable only in the LIDAR data, are interpreted to be the remnants of rootless phreatomagmatic cones. Glacial erosion has since excavated the highly fractured cone material, leaving the more resistant dike and quenched melt to form protruding ring structures. The ability to detect subtle variations in topography using LIDAR may identify previously undetected landscape elements.
Distributions and recent changes of carbon monoxide in the lower troposphere

Since 1988, the distribution of carbon monoxide (CO) in the lower troposphere has been determined using a globally distributed air sampling network. Site locations range from 82°N to 90°S, with wide longitudinal coverage, and represent the marine boundary layer, regionally polluted atmospheres, and the free troposphere. These measurements present a unique, intercalibrated, and internally consistent data set that are used to better define the global temporal and spatial distribution of CO. In this paper, times series from 49 sites are discussed. With an average lifetime of ∼2 months, CO showed significant concentration gradients. In the marine boundary layer, mixing ratios were greatest in the northern winter (200-220 ppb) and lowest in the southern summer (35-45 ppb). The interhemispheric gradient showed strong seasonality with a maximum difference between the high latitudes of the northern and southern hemispheres (160-180 ppb) in February and March and a minimum in July and August (10-20 ppb). Higher CO was found in regions near human development relative to those over more remote areas. The distributions provide additional evidence of the widespread pollution of the lower atmosphere. Remote areas in the high northern hemisphere are polluted by anthropogenic activities in the middle latitudes, and those in the southern hemisphere are heavily influenced by the burning of biomass in the tropics. While tropospheric concentrations of CO exhibit periods of increase and decrease, the globally averaged CO mixing ratio over the period from 1990 through 1995 decreased at a rate of approximately 2 ppb yr -1 .
Magmatic garnet in the Triassic (215 Ma) Dehnow pluton of NE Iran and its petrogenetic significance

The Triassic Dehnow pluton of NE Iran is a garnet-bearing I-type calc-alkaline metaluminous diorite-tonalite-granodiorite intrusion. The parental magma formed as the result of partial melting of intermediate to felsic rocks in the lower crust. Petrological and geochemical evidence, which indicates a magmatic origin for the garnet, includes: large size (~10–20 mm) of crystals, absence of reaction rims, a distinct composition from garnet in adjacent metapelitic rocks, and similarity in the composition of mineral inclusions (biotite, hornblende) in the garnet and in the matrix. Absence of garnet-bearing enclaves in the pluton and lack of sillimanite (fibrolite) and cordierite inclusions in magmatic garnet suggests that the garnet was not produced by assimilation of meta-sedimentary country rocks. Also, the δ18O values of garnet in the pluton (8.3–8.7‰) are significantly lower than δ18O values of garnet in the metapelitic rocks (12.5–13.1‰). Amphibole-plagioclase and garnet-biotite thermometers indicate crystallization temperatures of 708°C and 790°C, respectively. A temperature of 692°C obtained by quartz-garnet oxygen isotope thermometry points to a closure temperature for oxygen diffusion in garnet. The composition of epidote (Xep) and garnet (Xadr) indicates ~800°C for the crystallization temperature of these minerals. Elevated andradite content in the rims of garnet suggests that oxygen fugacity increased during crystallization.
On the relationships between the 40Ar-39Ar dating results and the conditions of basaltic samples

Based on the 40Ar-39Ar results for Deccan Traps samples, we have investigated the relationships between the 40Ar-39Ar age release pattern and conditions of basaltic samples. 40Ar-39Ar age release patterns are divided into five types, which might be related to the conditions of samples such as their petrological textures and alteration state. A peak of non-radiogenic component of Ar is observed at the temperature around 800°C in the Ar release patterns of Deccan Traps samples. Based on the above observations, criteria for sample selection and data treatment for the 40Ar-39Ar dating are summarized as follows. (1) It is recommended to use fresh samples as much as possible and minimize the use of samples which contain mesostasis. (2) Fine-grained holocrystalline rocks are preferable to get reasonable 40Ar-39Ar ages. (3) If a sample is affected by secondary alteration and shows a high 36Ar release in the intermediate temperature fractions, in age calculation it is better to exclude the isotopic data for the temperature fractions lower than about 800°C where the high 36Ar release is observed.
Features of the crust-mantle structure of Himalayas-Tibet: a comparison with seismic traverses of Alpine, Pyrenean and Variscan orogenic belts

Seismic data able to resolve the crustal structure are limited in quantity and quality with respect to the size and complexity of Tibet—Himalayas. They may be interpreted as indicating a strong heterogeneity: lack of continuity of even major interfaces across strike, defining different crustal blocks, but also lack of continuity of surface tectonic features down through the whole lithosphere. A thickening by imbrication of both the upper crustal and the lower crust-upper mantle levels is suggested. Indications from recent high-resolution surveys in other domains of thickened crust are also of a less smooth geometry of structures and depth than intuitively considered.