Miracle-dz/UniFAR-FTUs huggingface dataset:
Continental-shelf progradation by sediment-drift accretion

Multi-channel seismic profiles from the Canterbury Basin on the eastern margin of the South Island of New Zealand reveal the importance of current activity in shaping a Neogene shelf sediment prism. The shelf prism prograded across a broad, near-horizontal platform in water depths of 1,000 to 1,750 m. The platform was formed above a condensed section of late Eocene to late Oligocene limestones which overlie Cretaceous to Paleogene rift-fill and transgressive sediments. The Neogene sediment prism contains sediment drifts which are as much as 25 km long and 15 km wide and extend up to 1,600 m (uncompacted) vertically. Individual drifts migrated westward and can be traced between dip profiles, revealing that the long axes of most are subparallel to the present coastline and shelf-edge. Channel-like features at the landward edges of the drifts correspond to residual space left between the landward-prograding off-shelf sediment drift and the adjacent shelf foreslope. Erosion or slow deposition characterized the foreslope. Progradation of the shelf was by the accretion of successive sediment drifts. Before ca. 11.5 Ma (= Pink Horizon), the shelf-edge-parallel drifts were distributed across the central part of the basin, whereas subsequently they were concentrated to the northeast. The seismic architecture of the Neogene sediment prism results from the interplay of an abundant western sediment source and an offshore boundary current system. Present-day ocean circulation involves northward flow along the east coast of the South Island. The basin may have been subjected to a middle Miocene to late Pliocene phase of intensified flow, caused by local topographic enhancement and/or global paleoceanographic events. Current activity has played a crucial role in the sedimentary evolution of the Canterbury Basin Neogene shelf prism.
Constraints on Pennsylvanian glacioeustatic sea-level changes using oxygen isotopes of conodont apatite

Conodonts from U.S. Midcontinent cyclothems were studied for oxygen isotopes in order to constrain Pennsylvanian glacioeustatic sea-level fluctuations. Pennsylvanian deposits of the Midcontinent United States are composed of cyclic alternations of thin transgressive limestones, offshore gray to black phosphatic shales, and thick regressive limestones, a sequence that is underlain and overlain by nearshore to terrestrial shales with paleosols and coal beds. Glacioeustatic sea-level fluctuations are considered the primary cause for the formation of these cyclothems. Oxygen isotope analyses of conodont apatite from the black (20.1 ± 0.5‰, Vienna standard mean ocean water [VSMOW]) and gray shale units (20.5 ± 0.5‰, VSMOW) show lowest average δ 18 O values, whereas conodont elements from the regressive (21.0 ± 0.3‰, VSMOW) and transgressive limestone units (21.1 ± 0.6‰, VSMOW) are enriched in 18 O. The maximum change in δ 18 O of conodonts from the black shale and carbonate units from individual cyclothems is 1.7‰. The 1.7%c difference in δ 18 O compares relatively well to Pleistocene interglacial-glacial changes in δ 18 O of equatorial surface-dwelling foraminifers and suggests that Pennsylvanian glacioeustatic sea-level changes may have been of comparable amplitude. However, since the Pennsylvanian glacial maxima are represented by terrestrial sediments and are not documented in the conodont oxygen isotope record, Pennsylvanian glacioeustatic sea-level changes were probably larger than the 120 m fluctuations recorded for the Pleistocene glaciations.
Mapping Cotton Root Rot Infestations with Airborne Multispectral Imagery

Cotton root rot, caused by the fungus Phymatotrichum omnivorum, is a serious and destructive disease that significantly reduces cotton yield and lowers lint quality. Cultural practices are commonly recommended for the control of cotton root rot, while fungicides and fumigants that may suppress the disease have been used. Because of the high costs of these chemicals, their use may be economically feasible only when the infested portions of the field are treated. The objective of this study was to evaluate airborne multispectral imagery for detecting and mapping root rot infestations in cotton fields for site-specific management of the disease. One center pivot-irrigated field and one rainfed field near Corpus Christ, Texas were selected for this study. Airborne multispectral digital imagery was taken from the two fields shortly before harvest in 2001 when the infested areas with wilted and dead plants were fully pronounced for the season. The imagery was georeferenced and then classified into healthy and infested areas using unsupervised classification. Accuracy assessment on the classification maps for the two fields indicated airborne imagery effectively and accurately identified root rot infested areas within the fields. Ground samples taken from the fields showed that cotton yield and some lint quality indices were significantly lower in infested areas than in healthy areas. Buffer zones around the infested areas were generated to account for the spread of cotton root rot on the root rot maps. The mapping procedures and maps presented in this study will be useful for site-specific management of the disease.
Cloud cover from high-resolution scanner data - Detecting and allowing for partially filled fields of view

We present a new technique for obtaining cloud cover and determining clear sky radiances using high-resolution infrared scanner data. The technique, which can be automated, uses the spatial structure of the IR radiance field to identify radiances associated with fields of view that are either free of clouds or completely covered by clouds drawn from one or more distinct layers. As the method uses only infrared radiances, it should provide equally good results for both daytime and nighttime observations. The approach is particularly suited for determining clear sky radiances over oceans from which sea surface temperature might be derived. In addition, for single-layered systems, the cloud cover fraction for a given region may be obtained from the clear sky radiance, the completely cloud covered radiance, and the mean radiance for the region. For such systems the separation of completely covered from partially covered fields of view allows an estimate of the errors associated with commonly used threshold techniques for determining cloud cover. These errors are, in general, shown to be highly sensitive to the applied threshold and to depend on the cloud-areal size distribution. In addition, unlike the spatial coherence method described here, histograms and correlations of visible and IR radiances as proposed for archiving information on cloud cover may fail to reveal the layered structure of cloud systems. Furthermore, the high local structure observed for the visible radiances of regions that appear to be completely cloud covered makes it impossible to obtain reliable estimates of the cover from visible radiances alone.
Nitrogen mineralization in Florida Histosols.

The N-mineralization rates of several Florida Histosols and the effects of soil moisture tension and organic C amendments on these rates were measured in the laboratory with an ¹⁵N-tracer technique. An enhancement of microbial activity by crop residues was exhibited by greater N mineralization in cropped vs. uncropped soils. Nitrogen mineralization was not affected by soil moisture tension over the range of 0.1 to 3.0 bar. Exogenous C supplies such as glucose or St. Augustinegrass [Stenotaphrum secundatum (Walt.) Kuntz] stimulated mineralization of native soil organic matter. Mineralization of soil organic N was increased by 91% in glucose amended soil samples. The N-mineralization rate for a 75-cm profile of Pahokee muck was estimated to be 686 kg N/ha for each centimeter of soil lost to microbial oxidation.
Temporal burn scar evolution in tallgrass prairie based on field spectroscopy

In situ field spectroscopy samples were used to simulate several Moderate Resolution Imaging Spectroradiometer (MODIS) bands and indices commonly used for burned area detection. Each band or index was tested for its ability to differentiate between burned and unburned tallgrass prairie during several time periods from spring (when burning took place) to late summer (peak biomass) with three analysis of variance tests. The normalized difference vegetation index (NDVI), global environmental monitoring index (GEMI), global environmental monitoring index – burn scar (GEMI-B), and normalized burn ratio (NBR) indices, as well as MODIS band 7 (longwave mid-infrared; LWMIR), showed virtually no promise for differentiating burned from unburned areas for more than several days after the burn. Others, including the burned area index (BAI), Mid-infrared burn index (MIRBI), and MODIS bands 3 (red), 4 (near-infrared; NIR), 5 (longwave near-infrared; LWNIR), and 6 (shortwave mid-infrared; SWMIR) were able to differentiate between burned and unburned areas well into the growing season – in some cases, even through its entire length. The performance of particular bands and indices often depended on grazing, vegetation phenology, ash/char/soil reflectance, and factors that influenced pre-burn biomass.
Perturbations to tropospheric oxidants, 1985–2035: 1. Calculations of ozone and OH in chemically coherent regions

A one-dimensional photochemical model has been used to calculate future changes in tropospheric O{sub 3} and OH due to CO/NO{sub x}/CH{sub 4} emissions and to possible changes in stratospheric O{sub 3} and tropospheric H{sub 2}O. Perturbations are simulated for various chemically coherent regions (e.g., urban and continental mid-latitudes, and marine and continental low latitudes) from 1985 to 2035. Estimates of global changes in O{sub 3} and OH are made by averaging over these regions. Two types of scenarios are simulated. Global scenarios assume that increases of CH{sub 4} and CO continue at current rates in all regions. A second set of scenarios, based on an analysis of CH{sub 4}, CO, and NO budgets in each region, assumes that emissions will be controlled in some regions and not in others. Both global and region-specific scenarios predict a global tropospheric O{sub 3} increase of {approximately}10-15% from 1985 to 2035 with OH decreasing 10-15%. In the regionally varying scenarios, O{sub 3} will increase in some regions and decrease in others; for examples in regions of rapid CH{sub 4} and CO increase, growth in boundary layer O{sub 3} may be as high at 40%. Calculations that assume stratospheric O{sub 3} depletion and climate warmingmore » from 1985 to 2035 show near cancellation of the tropospheric O{sub 3} enhancement and OH loss. All scenarios of CH{sub 4}/CO/NO changes considered in this study imply a 1-1.5% increase in total ozone from 1985 to 2035, assuming that tropospheric O{sub 3} is 10% of the total O{sub 3} column. This may complicate detection of stratospheric O{sub 3} change by monitoring of total O{sub 3}. « less
Enhancement of ultralow frequency wave amplitudes at the plasmapause

We present measurements of ultralow frequency (ULF) wave amplitudes measured by the Time History of Events and Macroscale Interactions during Substorms (THEMIS) probes while crossing the plasmapause. During one crossing on 24 June 2007 which we study in detail, all three probes of which data that were obtained show an increase in the ULF compressional wave amplitude between 10 and 50 mHz by about 30%. These results are confirmed by a statistical study that examines the ULF compressional wave amplitude in the same frequency range averaged over 132 sharp plasmapause crossings between June 2007 and December 2007 made by THEMIS C, D, and E. Sharp plasmapause crossings are defined as those where the density increases by more than a factor of 50 over a spatial scale of 500 km. We find that assuming that the plasmapause can be approximated by a tangential MHD discontinuity, a ULF wave amplitude enhancement of 30% is in good agreement with theoretical transmission coefficient calculations if the plasma density increases from about 4 cm−3 on the magnetospheric trough side to about 540 cm−3 on the plasmaspheric side while simultaneously the magnetic field magnitude increases from 250 nT to 350 nT. These results might have important implications for the detection of global fast modes by satellites as their amplitude is hence expected to be higher inside the plasmasphere than outside.
Changes in Catchment‐Scale Recession Flow Properties in Response to Permafrost Thawing in the Yukon River Basin

Permafrost influences the hydrologic response of a catchment. In this study, we test the ability of recession flow analysis to reflect thawing of permafrost at the catchment scale for the well‐studied Yukon river basin (YRB), covering large portions of Alaska, USA and parts of Canada. The changes in the recession flow properties detected in the YRB agree well with observations of permafrost thawing across central Alaska. In addition, there is good agreement between the relative increases in recession flow intercept (a proxy for effective depth to permafrost) and the relative annual increases in groundwater flow (independently assessed as a permafrost thawing effect) in the YRB catchments that have exhibited such groundwater flow increases. This study demonstrates the utility of recession flow analysis to reflect catchment‐scale changes in permafrost across a variety of permafrost conditions. The strength of this method is that it requires only daily observations of streamflow to reflect permafrost thawing on much larger measurement support scales than the local scales of direct permafrost observations. Copyright © 2009 Royal Meteorological Society
Vacuum BRDF Measurements Of Cryogenic Optical Surfaces

Spaceborne optical systems designed for long-duration missions are susceptible to degradation from contaminants in the spacecraft environment. In order to assess contamination build-up rates and corresponding scatter changes, we have designed a BRDF measurement system for use in a high-vacuum (10-8 Torr), low-temperature (20K) environment. The system measures cryocooled optics at angles from near-specular (< 1°) to approximately 30° off-axis, at wavelengths of 0.633 and 10.6 microns. We describe the design characteristics of the instrument, and discuss preliminary experiments which demonstrate contamination build-up correlated with changes in the sample BRDF profiles. The current status of the instrument is reviewed and future plans and applications summarized.
Low-Mass X-Ray Binaries and Globular Clusters in Early-Type Galaxies. I. Chandra Observations

We present a Chandra survey of LMXBs in 24 early-type galaxies. Correcting for detection incompleteness, the X-ray luminosity function (XLF) of each galaxy is consistent with a power law with negative logarithmic differential slope, β ∼ 2.0. However, β strongly correlates with incompleteness, indicating the XLF flattens at low-LX. The composite XLF is well fitted by a power law with a break at (2.21+ 0.65−0.56) × 1038 ergs s−1 and β = 1.40+ 0.10−0.13 and 2.84+ 0.39−0.30 below and above it, respectively. The break is close to the Eddington limit for a 1.4 M☉ neutron star, but the XLF shape rules out its representing the division between neutron star and black hole systems. Although the XLFs are similar, we find evidence of some variation between galaxies. The high-LX XLF slope does not correlate with age, but may correlate with [α/Fe]. Considering only LMXBs with LX > 1037 ergs s−1, matching the LMXBs with globular clusters (GCs) identified in HST observations of 19 of the galaxies, we find the probability a GC hosts an LMXB is proportional to LαGCZγFe where α = 1.01 ± 0.19 and γ = 0.33 ± 0.11. Correcting for GC luminosity and color effects, and detection incompleteness, we find no evidence that the fraction of LMXBs with LX > 1037 ergs s−1 in GCs (40%), or the fraction of GCs hosting LMXBs (~6.5%) varies between galaxies. The spatial distribution of LMXBs resembles that of GCs, and the specific frequency of LMXBs is proportional to the GC specific luminosity, consistent with the hypothesis that all LMXBs form in GCs. If the LMXB lifetime is τL and the duty cycle is Fd, our results imply ~1.5(τL/108 yr )−1F−1d LMXBs are formed per gigayear per GC, and we place an upper limit of one active LMXB in the field per 3.4 × 109 L☉ of V-band luminosity.
P wave velocity across a noncoaxial ductile shear zone and its associated strain gradient: Consequences for upper crustal reflectivity

In order to simulate a normal incidence reflection profile across a noncoaxial ductile shear zone, we determined P wave velocities of samples cut parallel and normal to mylonite foliation along a closely spaced profile (≈ 27 cm long) through a transition zone and its associated strain gradient. The ductile shear zone, developed within an aplitic leucogranite, was sampled from a kilometer-wide ductile transcurrent fault in the northern French Massif Central. Strain analysis indicates that the sample experienced heterogeneous and progressive simple shear deformation; shear strain (γ) systematically increases from zero in the undeformed protolith to ≈ 30 in the mylonite. The transition zone thickness (T) is about 30 cm, and the mylonite thickness (M) is about 10 cm. The amount of quartz and mica increases relative to feldspar toward the mylonite, indicating that a mineralogical composition change accompanied mylonitization. Mica and quartz developed a strong crystallographic preferred orientation (CPO). In the least strained domain, seismic anisotropy is low and mean Vp is 6 km/s at 600 MPa. Anisotropy increases up to 10% and Vp decreases up to 5.35 km/s for propagation normal to the mylonite foliation through the transition zone. This systematic velocity change correlates with the increasing γ through the transition zone and can be directly related to the CPO of mica and the increase in volume percent mica within the mylonite zone. These results indicate that velocity and anisotropy gradients may, in some cases, be associated with ductile shear zones and that mylonite boundaries may not represent first-order discontinuities. The reflectivity of a ductile shear zone depends on the thickness of the transition zone relative to the seismic wavelength (λ) and on the T/M ratio. Synthetic seismograms show that for a given seismic wavelength the reflectivity decreases when the transition zone thickness increases and when the ratio T/M increases. We show that layers with second-order boundaries (velocity gradients in transition zones) are only seismically detectable within a narrow thickness range. Extrapolation to thicker shear zones is based on the assumption that the strain gradient thickness relative to shear zone thickness is, to a first approximation, scale independent. In granitic domains, ductile shear zones with similar geometrical and petrophysical features to the example studied here will be detected on deep seismic profiles only if their width is between 20 and 400 m. Development of ductile shear zones with strain gradients of the appropriate thickness to enhance reflectivity is favored under low-temperature conditions in the granitic upper crust. Indeed, low-temperature strain gradient may explain the high seismic reflectivity of the upper crust in the Scandinavian Caledonides, whereas high-temperature strain gradient may explain, in part, the relative transparency of the European Variscan upper crust.
Ascent of magma in a deformable vent

The ascent of magma in a deformable cylindrical vent is analyzed to reveal the character and extent of mechanical disturbances in vent geometry and associated effects on the magma ascent process. Both magma and surrounding country rock are assumed to behave as Newtonian fluids. According to the analysis, any disturbance involving the deformation of conduit is transmitted upward at approximately same speed as magma motion, while the disturbance hardly influences the state below. In particular, irregular vent geometry containing a bump or a constriction propagates upward like a wave, being accompanied by a pressure dipole that is composed of a pair of positive and negative pressure deviations. Since magma flux is strongly controlled by the pressure below, the persistence of high magma pressure in the magma reservoir favors expansion of the vent and can lead to a volcanic eruption. On the contrary, a low magma pressure tends to result in the closure of the conduit above. Therefore if the effective viscosity of the country rock is sufficiently low as might be the case when it is partially molten, a vent can be flexibly opened or closed in response to pressure in the magma reservoir.
Self‐organized criticality of plastic shear bands in rocks

We show that the shear bands that appear during the pure shear numerical simulations of rocks with a non-associated plastic flow rule form fractal networks. The system drives spontaneously into a state in which the length distribution of shear bands follows a power law (self-organized criticality) with exponent 2.07. The distribution of local gradients in deviatoric strain rate has different scaling exponents for each moment, in particular the geometrical fractal dimension is 1.7. Samples of granodiorite sheared under high confining pressure from the Pyrenees are analyzed and their properties compared with the numerical results.
Nostradamus: The radar that wanted to be a seismometer

Surface waves emitted after large earthquakes are known to induce, by dynamic coupling, atmospheric infrasonic waves propagating upward through the neutral and ionized atmosphere. Those waves have been detected in the past at ionospheric heights using a variety of techniques, such as HF Doppler sounding or GPS receivers. The HF Doppler technique, particularly sensitive to the ionospheric signature of Rayleigh waves is used here to show ionospheric perturbations consistent with the propagation of Rayleigh wave phases R1 and R2 following the Sumatra earthquake on the 28 March 2005 (M = 8.6). This is in our knowledge the first time that the phase R2 is detected by ionospheric sounding. In addition, we prove here that the ionospheric signature of R2 is also observed by over‐the‐horizon (OTH) Radar. The latter was never used before to detect seismic signature in the ionosphere. Adding the OTH Radar to the list of the “ionospheric seismometers” we discuss and compare the performances of the three different instruments mentioned above, namely HF Doppler sounding, GPS receivers and OTH radar.
Rapid detection of tobacco viruses by reverse transcription loop-mediated isothermal amplification

Tobacco viruses may cause a wide range of diseases that heavily reduce tobacco quality and yield worldwide. In order to detect viral diseases in tobacco fields, a one-step reverse transcription loop-mediated isothermal amplification (RT-LAMP) method was established. Nucleotide amplification could be observed clearly after adding SYBR Green I, within 60 min under isothermal conditions, at 63-65 °C with a set of primers targeting the viral coat protein (CP) genes of tobacco viruses including cucumber mosaic virus (CMV), potato virus Y (PVY), tobacco etch virus (TEV), tobacco mosaic virus (TMV) and tobacco vein banding mosaic virus (TVBMV). This method has high specificity and sensitivity. The sensitivity of the RT-LAMP was 10 to 100 times higher than that of the conventional RT-PCR method. The RT-LAMP assay was proven reliable for virus diagnosis of tobacco samples from the field.