Miracle-dz/UniFAR-FTUs huggingface dataset:
Effects of sedimentation, tectonics, and glacio-eustasy on depositional sequences, Pennsylvanian Minturn Formation, north-central Colorado

The Pennsylvanian Minturn Formation was deposited adjacent to the Ancestral Front Range on the eastern margin of the actively subsiding Central Colorado Basin during a time of high-frequency eustatic sea level changes attributed to glaciations in the Southern Hemisphere. In the 100 km2 study area near McCoy, Colorado, up to nine depositional cycles composed of marine and nonmarine deposits are recognized. Three tectonic blocks were subsiding at different rates in the study area. Detailed correlation of measured sections along well-exposed outcrop belts has shown that seven of these cycles extend continuously across the field area, which includes two delta complexes. Two cycles are absent on the central block. The study area is well suited for examining the role of local tectonic vs. eustatic processes in controlling the distribution of sedimentary deposits. In the study area, cycles are bounded by erosional surfaces with as much as 43 m of relief. These surfaces are inferred to be sequence boundaries and are overlain by braided fluvial conglomerates inferred to be incised valley-fill deposits. Marine flooding surfaces overlie the conglomerates. The ©Copyright 1997. The American Association of Petroleum Geologists. All rights reserved.1Manuscript received January 17, 1996; revised manuscript received October 18, 1996; final acceptance March 20, 1997. 2Department of Geological Sciences, University of Colorado at Boulder, Campus Box 250, Boulder, Colorado 80309-0250. Present address: Department of Geology, University of Colorado at Denver, Campus Box 172, P.O. Box 173364, Denver, Colorado 80217-3364. I thank the members of my doctoral dissertation committee at the University of Colorado (Ted Walker, Martin Lockley, Alan Scott, David Budd, and John Pitlick) for their advice and guidance during the course of my research. Financial support was provided by the Rocky Mountain Section of SEPM, the Colorado Mountain Club, Union Pacific Resources, and the Department of Geological Sciences at Colorado University-Boulder. Charles Ross provided fusulinid identifications and biostratigraphic zonation. I thank Paul Weimer (Colorado University-Boulder) for advice and encouragement, and Keith Miller (Kansas State University) for carefully reviewing a preliminary draft of this paper. AAPG reviewers William Devlin, Romeo Flores, Denise Stone, and Elected Editor Kevin Biddle provided many suggestions that greatly improved the final manuscript. I also thank the residents of McCoy, Bond, and Copper Spur, Colorado, for granting access to their property, and for all their kindness while I was working in the field.
Evidence for protracted prograde metamorphism followed by rapid exhumation of the Zermatt‐Saas Fee ophiolite

Major and trace‐element zoning in garnet, in combination with Rb–Sr, Sm–Nd and Lu–Hf geochronology, provide evidence for a protracted garnet growth history for the Zermatt‐Saas Fee (ZSF) ophiolite, western Alps. Four new Lu–Hf ages from Pfulwe (c. 52–46 Ma) and one from Chamois (c. 52 Ma) are very similar to a previously published Lu–Hf age from Lago di Cignana. Overall, the similarity of geochronological and garnet zoning patterns suggests that these three localities had a similar prograde tectonic history, commensurate with their similar structural position near the top of the ZSF. Samples from the lower part of the ZSF at Saas Fee and St. Jacques, however, produced much younger Lu–Hf ages (c. 41–38 Ma). Neither differences in whole‐rock geochemistry, which might produce distinct garnet growth histories, nor rare‐earth‐element zoning in garnet, can account for the age differences in the two suites. This suggests a much later prograde history for the lower part of the ZSF, supporting the idea that it was subducted diachronously. Such a model is consistent with changes in subduction vectors based on plate tectonic reconstructions, where early oblique subduction, which produced long prograde garnet growth, changed to more orthogonal subduction, which corresponds to shorter prograde garnet growth. Six new Rb–Sr phengite ages range from c. 42 to 39 Ma and, in combination with previously published Rb–Sr ages, constrain the timing of the transition from eclogite to upper greenschist facies P–T conditions. The proximity of the ZSF in the Saas Fee region to the underlying continental Monte Rosa unit and the similarity of peak‐metamorphic ages suggest these two units were linked for part of their tectonic history. This in turn indicates that the Monte Rosa may have been partly responsible for rapid exhumation of the ZSF unit.
A physical model for widespread near‐surface and fault zone damage induced by earthquakes

I present a rigorous unifying interpretation of the well‐documented widespread near‐surface and fault zone damage induced by earthquakes by simulating three‐dimensional dynamic rupture propagation on a vertical strike‐slip fault. Stresses in the crust are depth‐dependent and material response is governed by the Drucker‐Prager yielding criterion. I show that material yielding induced by seismic waves under the low confining pressure causes widespread near‐surface damage. Because the confining pressure increases with depth, the yielding zone at depth is narrowly confined near the fault, but its thickness broadens dramatically near the surface, forming a “flower‐like” damage zone. The fault zone damage at depth is induced by large dynamic stresses associated with the rupture front, while is induced by strong seismic waves ahead of the rupture front near the Earth's surface. These results have important implications for the formation and evolution of fault zones and possibly for the dynamic triggering of earthquakes as well.
Sustainable Urban Development: A Literature Review and Analysis

This report reviews current literature on sustainable development and proposes a framework for applying this concept to city and regional planning. It begins by exploring interpretations of the concept of sustainability itself, next looks at some urban planning traditions toward an urban planning framework that can incorporate this concept. The following definition of sustainable urban development is proposed: Sustainable urban development seeks to create cities and towns that improve the long-term health of the planet’s human and ecological systems. Means to achieve this objective include protecting and restoring natural ecosystems in urban areas, creating community environments that nurture human potential, using land and resources wisely, and facilitating human lifestyles that contribute to global sustainability. The author argues that sustainable urban development is indeed possible if 1) some degree of consensus is reached on values that can underlie it, 2) methods are developed to evaluate progress towards or away from sustainability, 3) specific policies, designs and programs are developed to implement sustainable urban development based on these values and yardsticks, and 4) the necessary political organizing, leadership development, and public education can be carried out.
Evaluation of the characteristics of 14 cover crops used in a soil rehabilitation trial

Many of the soils in Santa Cruz Department, Bolivia, are degraded by serious weed infestation, subsoil compaction, and low organic matter and nitrogen contents. Fallow periods with cover crops are frequently used to recuperate the fertility of degraded soils, but little information exists on the desired characteristics of cover crops for this purpose. The aim of this study was to describe those characteristics, believed to be most relevant to the rehabilitation of degraded soils in Santa Cruz, of 14 cover crops, which included three grasses, nine legumes, and two winter cover crops sown after summer soybean (Glycine max). The cover crop characteristics, evaluated over two years, were ease of establishment, competitiveness against weeds, tolerance to drought, dry matter production and nutrient contents of the above-and below-ground residues, nodulation, rooting density and root diameters. The three grasses Tobiata (Panicum maximum var. Tobiatd), Centenario (Panicum maximum var. Centenario) and Brizantha (Brachiaria brizantha) appeared to be the most promising for increasing soil organic matter contents, and the three grasses and groundnuts (Arachis hypogaea)/pigeon pea (Cajanus cajan) for the recuperation of subsoil structure. Mucuna deeringiana and Lablab (Dolichos lablab) were the most promising for increasing soil N status. All of these cover crops competed successfully with weeds.
Slab avalanche measurements

From a study of 205 slab avalanches it is concluded that failure initiates where the slope is 25° or steeper, that slab failure stress is in the range 102–104 N/m2, and that the slab failure plane is most commonly at a temperature of −5 °C or warmer.The in situ measurement of shear strength is still an unresolved problem. A statistical analysis of a shear-frame device shows that the device is sensitive to the rate of pull and to the frame area. The larger the frame area, the smaller the measured shear strength. Approximately 10 measurements are required to sample a mean shear strength of a slab failure plane to within 15% accuracy at 90% confidence.
A New Locality Records of Stellagama stellio (Linnaeus, 1758) (Sauria: Agamidae) in Anatolia

As a result of our study, the new data on distribution of Stellagama stellio (Linnaeus, 1758) in Anatolia were obtained. The meristic pholidolial, metric (morphometric) characters and color-pattern features of specimens of S. stellio collected from five new localities in Turkey were given in detail and compared with regard to literature. Specimens examined in the present study were similar to S. s. daani specimens mentioned in the literature.
The influence of temperature on the small-strain viscous deformation mechanics of snow: a comparison with polycrystalline ice

Abstract Glen’s law is commonly used to model the viscous deformation of polycrystalline ice. It is a power law that relates stress to viscous strain rate and contains three material parameters: n, a power-law exponent, Q, an activation energy, and A 0, a material constant. Because polycrystalline ice is the constituent material of snow, it is to be expected that the viscous deformation mechanics of snow are related to the viscous behaviour of polycrystalline ice, especially under small strains and low strain rates when kinematic effects in the ice matrix like bond breakage, bond formation and grain sliding are of secondary importance. Based on 64 deformation-controlled compression tests on fine-grained snow in the density range 200–430kg m–3 and temperature range T = –20 to –2°C, we show that Glen’s law—with material parameters similar to those for polycrystalline ice—can be applied to model the viscous deformation of high-density snow However, the values of the ice material parameters are valid for densities above a relatively low density of 400 kg m–3; they are not valid for snow with densities below 360 kg m–3. We present the variation of n, Q and A for snow as a function of density and temperature. A possible explanation for this behaviour is that the ice grains in low-density snow are less constrained. Therefore, deformation mechanisms, such as grain-boundary sliding, increase in overall importance, leading to smaller n values and higher activation energies, Q. Although the material behaviour of low-density snow can be accurately modelled using a power law, the power-law parameters depart substantially from those of polycrystalline ice. The large variation of n and Q with temperature and density underscores the difficulty of predicting snow avalanches.
The Effects of Low-Frequency Climate Oscillations on Interannual Variations in East Coast Winter Storm Tracks

Correlations between low-frequency climate oscillations and East Coast Winter Storm location are explored using the Hirsch et al. (2001) definition of ECWS and NCEP Reanalysis data. Relevant climatic factors are identified, and comparisons are drawn in ECWS geographic frequency between significant positive and negative phases of these climate oscillations through an automated procedure. It is found that the Multivariate ENSO Index, the North Atlantic Oscillation, the Arctic Oscillation, and the Pacific Decadal Oscillation are significantly correlated to ECWS frequency at specified grid points along the East Coast. Furthermore, it is apparent that select modes of these climate oscillations have a more profound effect on ECWS frequency than others: A positive ENSO keeps storms on a more southerly route; A negative NAO and AO confine storms to the midand north coast; and a negative PDO moves storms to the north. Maps of average 500 mb heights during these storm days are created and sorted by sign and magnitude of climate index, and aid to an explanation of storm motion through temperature and height gradients as well as trough axis position.
Finite element methods for modeling water flow in variably saturated porous media: Numerical oscillation and mass‐distributed schemes

The finite element method is an attractive numerical method for modeling water flow in variably saturated porous media due to its flexibility in dealing with complicated geometries. It is well known that the conventional mass-distributed finite element method suffers from numerical oscillations at the wetting front, especially for very dry initial conditions. Routinely, mass-lumped procedures are used to eliminate them. This paper proposes a physical interpretation of the finite element method applied to the water flow problem. With the finite element method, mass conservation is applied at the element level. The water storage and the flux within each element are split into several components in the function space, each of which corresponds to one component of the boundary flux of the element. However, even though physical laws are correctly applied at the element level, it is shown that the traditional mass-distributed scheme can still generate an incorrect neighboring node response due to the highly nonlinear properties of water flow in unsaturated soil and cause numerical oscillation. We propose two new mass-distributed schemes which are free of the numerical oscillation, and reduce the smearing near the wetting front, at slightly increased CPU time.
Low altitude quasi‐periodic radar echoes observed by the Gadanki VHF radar

We report here on the low altitude quasi‐periodic (LQP) radar echoes from low latitude sporadic E layer (Es) observed by the Gadanki (13.5°N, 79.2°E; geomagnetic latitude 6.3°N) VHF radar. The LQP echoes occurred both during daytime and nighttime and are confined to a slowly descending layer with a thickness of about 2–4 km in the height range of 90–100 km. The periods are found to range from tens of seconds to less than about 3 minutes. The Doppler velocities vary over a range of −20 to +20 m/s during daytime and 0 to 10 m/s during nighttime and are known to be sensitive to the layer height, being dominated by the effect of zonal electric field above and meridional neutral wind below a height of ∼97 km for the type 2 irregularities [ Krishna Murthy et al., 1998 ]. The spectral widths are found to be of the order of 50 to 75 m/s during daytime and 30 to 60 m/s during nighttime. The LQP echoes reported here are similar to that observed recently over midlatitudes [ Rao et al., 2000 ; Urbina et al., 2000 ], but distinctly different from the widely reported quasi‐periodic (QP) echoes occurring at higher altitudes (>100 km). The observations are discussed briefly in terms of the potential source mechanisms.
Bedrock geology and topography of the Lake Peipsi depression, eastern Estonia

Abstract Seismic reflection profiling in the western part of Lake Peipsi, eastern Estonia, revealed two major units in the sedimentary bedrock, namely Devonian terrigenous rocks on top of Ordovician carbonate rocks. In the Ordovician sequence several subhorizontal reflectors and subvertical faults were recorded. The Ordovician-Devonian contact carries signs of erosion and has an inclination towards the south to southeast by 2-2.2 m per km in the northern and central parts and 4.5- 4.9 m per km in the southern part of the lake. The thickness of the Devonian terrigenous rocks increases rather abruptly in the southern part of the lake, approximately within the same zone where the inclination of the Ordovician-Devonian contact increases. Gently sloping depressions and elevations were distinguished at the bedrock surface, which dips towards the center of the lake. A buried valley in Devonian sedimentary bedrock was found in the northwestern part of the lake. The magnitude of the glacial erosion in the central part of the depression, as related to the altitude of the bedrock surface in the surrounding onshore areas, is estimated to at least 50-60 m. The glacial erosion has not been compensated by subsequent glacial accumulation and late- to postglacial lake sedimentation. Because of this, the main features of the bedrock topography are still traceable at the till surface as well as in the lake bottom topography.
Seasonal Gyres in the Northern Gulf of California

Abstract The circulation pattern in the northern Gulf of California, based on drifting buoys and hydrographic observations, can be explained using the results of a linear two-layer primitive equations model forced, at the annual frequency, by the Pacific Ocean, wind stress, and heat flux through the surface. The modeled surface circulation consists of a cyclonic gyre from June to October and an anticyclonic gyre from December to April, both located in the central region of the northern Gulf of California, which includes Angel de la Guarda Island. The maximum intensities of the gyres occur in August and February, respectively, with values of surface velocities of 65 cm s−1 (in agreement with the observations) and very low opposite velocities in the bottom layers. May and November are transition months in which both gyres can be observed. Finally, in June/July or December/January the growing gyre is still connected with the rest of the Gulf of California, through the narrows between Tiburon Island, San Este.
Erodibility of cohesive streambeds in the loess area of the midwestern USA

Excess stress parameters, critical shear stress (τc) and erodibility coefficient (kd), for degrading channels in the loess areas of the midwestern USA are presented based on in situ jet‐testing measurements. Critical shear stress and kd are used to define the erosion resistance of the streambed. The jet‐testing apparatus applies hydraulic stresses to the bed and the resulting scour due to the impinging jet is related to the excess stress parameters. Streams tested were primarily silt‐bedded in texture with low densities, which is typical of loess soils. Results indicate that there is a wide variation in the erosion resistance of streambeds, spanning six orders of magnitude for τc and four orders of magnitude for kd. Erosion resistance was observed to vary within a streambed, from streambed to streambed, and from region to region. An example of the diversity of materials within a river system is the Yalobusha River Basin in Mississippi. The median value of τc for the two primary bed materials, Naheola and Porters Creek Clay Formations, was 1·31 and 256 Pa, respectively. Streambeds composed of the Naheola Formation are readily eroded over the entire range of shear stresses, whereas only the deepest flows generate boundary stresses great enough to erode streambeds composed of the Porters Creek Clay Formation. Therefore, assessing material resistance and location is essential in classifying and modelling streambed erosion processes of these streams.
Effective Bass‐Paur 1985 ozone absorption coefficients for use with Dobson ozone spectrophotometers

Details are presented concerning the derivation of new, standard, effective ozone absorption coefficients for use with Dobson ozone spectrophotometers. The work was performed under auspices of the World Meteorological Organization (WMO) Global Ozone Research and Monitoring Program, with the goal of improving and standardizing ozone measurements throughout the world. The new coefficients, based on the laboratory measurements of Bass and Paur (1985), were sanctioned for use worldwide, beginning January 1, 1992, by the WMO Executive Panel on Environmental Pollution and Atmospheric Chemistry. The new coefficients, together with use of slightly improved Rayleigh molecular scattering coefficients also adopted as standard, yield total ozone amounts 2.6% smaller than values obtained during July 1, 1957 to December 31, 1991, derived from the use of Vigroux (1953, 1967) ozone absorption coefficients. Information is provided also on correcting ozone data obtained in the past to the new ozone absorption coefficient scale.
Breakdown of ENSO predictors in the 2000s: Decadal changes of recharge/discharge‐SST phase relation and atmospheric intraseasonal forcing

Variations in the warm water volume (WWV) of the equatorial Pacific and atmospheric forcing from intraseasonal variation (ISV) in the western equatorial Pacific are regarded as two good predictors of the subsequent El Niño/Southern Oscillation (ENSO), with a lead time of two to three seasons. Here we report that the robust predictability of these predictors for ENSO has changed in the 2000s. During 1981–2000, the recharge (discharge) of the WWV and strong (weak) ISV forcing preceded El Niño (La Niña) by two to three seasons. However, in the 2000s, the interrelationship between the WWV/ISV and following ENSO became weak, especially for the El Niño/La Niña events after 2005. Notably, the discharged phases of WWV that led to subsequent La Niña events were less observed since 2001. These changes may be caused by frequent occurrences of the “warm‐pool El Niño,” which is characterized by SST anomalies centered in the central equatorial Pacific.
Validation of MODIS retrieval aerosol optical depth and an investigation of aerosol transport over Mohal in north western Indian Himalaya

This study deals with the optical properties of aerosols during 2007 over Mohal (31.9º N, 77.12º E) in north western Indian Himalaya, investigated using ground-based measurements and multi-satellite data. The daily average (mean ± standard deviation) aerosol optical depth (AOD) at 500 nm, Ångström exponent and turbidity coefficient values were 0.2 ± 0.1, 1.1 ± 0.3 and 0.1 ± 0.1, respectively. About 84% of AOD values retrieved from satellites were found to be within an uncertainty limit with a significant correlation coefficient around 0.70. The present study suggests that AOD retrieval using the Moderate Resolution Imaging Spectroradiometer (MODIS) is able to characterize AOD distribution over Mohal. However, to eliminate systematic errors, the existing MODIS algorithm needs to be modified in view of the changing aerosol optical properties, especially during the biomass-burning period. To investigate the influence of aerosol transport, a multi-sensor approach in conjunction with back-trajectory analysis was used. The observed higher values of AOD during dust-loading days with simultaneous study of the space-borne lidar measurements as well as back-trajectory analysis suggest the influx of desert aerosols. Transport of dust aerosols on 12 April, 27 April and 1 June caused a significant reduction in surface-reaching solar irradiance by 43, 40 and 39 W m–2, respectively. Atmospheric forcing during these days increased by 33.8, 33.0 and 33.2 W m–2, which translates into atmospheric heating rates of 0.95, 0.93 and 0.93 K day–1, respectively. This indicates significant climatic implications due to arriving aerosols in north-western Indian Himalaya.