Miracle-dz/UniFAR-FTUs huggingface dataset:
Biogeography in the Annals

Abstract Biogeography has been consistently well represented in the Annals throughout the Association of American Geographers' first century. This sample of biogeographic research effectively illustrates the persistent questions explored by the subdiscipline as well as changes in the intellectual perspectives taken on them. Four fundamental issues occupied biogeographers throughout this period (spatial pattern and process, landscape change, human modification of biotic communities, and linking physical and biological systems), but shifting research emphases show clear parallels to the major paradigmatic trends of 20th-century geography, including environmental determinism, regionalism, positivism, and postmodernism. These shifts define a number of fairly distinct periods of research activity: an early (1904–1927) focus on equilibrium environmental control of biotic communities and their dynamics, regional analysis and vegetation mapping (1942–1966), an increasing emphasis on methodological sophistication that prompted emphasis of environmental variability (1967–1987), and a recent (1987–present) reexamination of landscape dynamics with a concern for heterogeneity in space and time.
The influence of diurnal temperatures on the hydrochemistry of a tufa‐depositing stream

At‐a‐station diurnal variations in carbonate hydrochemistry were measured during four observation periods at Davys Creek, a tufa‐depositing stream in central NSW, Australia. Major ion concentrations and continuously logged measurements of specific conductivity, pH and temperature showed that changes in the amount of CaCO3 deposited upstream of the study reach were directly related to changes in diurnal water temperatures, which control the rate of CO2 efflux to the atmosphere. The greatest upstream losses occurred during the mid‐afternoon water temperature peak, whereas the lowest upstream losses occurred at sunrise, when water temperatures were at their lowest. Cloudy days at all times of the year produced small diurnal water temperatures ranges (c. 2–5°C) and, consequently, relatively small changes in upstream CaCO3 loss (23–50 mg L−1) through the day. Clear sunny days, especially during summer months, produced large diurnal water temperature changes (up to c. 11°C), which in turn triggered diurnal changes in upstream CaCO3 loss of up to 100 mg L−1. By implication, the active reach of tufa deposition must advance downstream and increase in length during the evening and vice versa during the day. Given that the temperature of Davys Creek waters are a function of insolation, changes in the reach of tufa deposition under baseflow conditions are a direct function of the prevailing weather. This has implications for the palaeoclimatic interpretation of fossil tufa deposits. Copyright © 2003 John Wiley & Sons, Ltd.
Increased glacier runoff enhances the penetration of warm Atlantic water into a large Greenland fjord

Abstract. The retreat and acceleration of Greenland's marine-terminating outlet glaciers have been linked to ocean warming. However the mechanisms which control the transmission of this warming along fjords towards the glaciers remain poorly understood. The aim of this paper is to elucidate observed changes in water properties in Kangerdlugssuaq Fjord (KF), East Greenland using the Bergen Ocean Model (BOM). Model outputs are compared with observed potential temperature, salinity and velocity data to determine the principal controls on heat transport within KF and to estimate resulting submarine ice front melt rates of Kangerdlugssuaq Glacier (KG). The BOM includes wind, tidal and glacier runoff forcing and is able to replicate observed temperature and salinity profiles. Model results describe a robust four-layer estuarine flow, consisting of two distinct circulations. The shallow circulation (0–~ 60 m) is forced by surface wind stress and to a lesser extent supraglacial runoff, while the intermediate circulation (~ 60–500 m) is driven by runoff discharged into the fjord subglacially. Atlantic Water (AW) and warm Polar Surface Water (PSWw) are drawn into the fjord by the intermediate and shallow circulation cells respectively, in a pattern consistent with observations, and AW reaches KG over a single summer. Along-fjord heat transport towards KG increases significantly with both glacier runoff and coastal water temperature. A doubling of glacier runoff produces a 29% (48%) amplification of mean annual (summer) heat transport towards the KG terminus, increasing estimated mean annual (summer) submarine melt rates from 211 to 273 (842 to 1244) m yr–1. In contrast, heat transport towards KG in the surface ~ 60 m of the fjord decreases with rising glacier runoff because the enhanced down-fjord component of the intermediate circulation interferes with the up-fjord part of the shallow circulation. Thus, as ice sheet runoff increases, KG's dynamic response to oceanic forcing will likely be driven primarily by enhanced submarine ice front melting and consequent undercutting rather than through diminished buttressing from seasonal sea ice and ice melange. Our model shows, in agreement with observations, that maximum submarine melt rates occur when AW and PSWw are present at the fjord mouth and, crucially, glacier runoff is also high. Rising ice sheet runoff therefore increases the sensitivity of KG (and other Greenland marine-terminating glaciers) to ocean warming.
Siderophile elements in Earth's upper mantle and lunar breccias: Data synthesis suggests manifestations of the same late influx

Abstract— The platinum group elements (PGE; Ru, Rh, Pd, Os, Ir, Pt), Re and Au comprise the highly siderophile elements (HSE). We reexamine selected isotopic and abundance data sets for HSE in upper mantle peridotites to resolve a longstanding dichotomy. Re‐Os and Pt‐Os isotope systematics, and approximately chondritic proportions of PGE in these rocks, suggest the presence in undepleted mantle of a chondrite‐like component, which is parsimoniously explained by late influx of large planetisimals after formation of the Earth's core and the Moon. But some suites of xenolithic and orogenic spinel lherzolites, and abyssal peridotites, have a CI‐normalized PGE pattern with enhanced Pd that is sometimes termed “non‐chondritic”. We find that this observation is consistent with other evidence of a late influx of material more closely resembling enstatite, rather than ordinary or carbonaceous, chondrites. Regional variations in HSE patterns may be a consequence of a late influx of very large objects of variable composition.
Effect of isolated fractures on accelerated flow in unsaturated porous rock

Fractures that begin and end in the unsaturated zone, or isolated fractures, have been ignored in previous studies because they were generally assumed to behave as capillary barriers and remain nonconductive. We conducted a series of experiments using Berea sandstone samples to examine the physical mechanisms controlling flow in a rock containing a single isolated fracture. The input fluxes and fracture orientation were varied in these experiments. Visualization experiments using dyed water in a thin vertical slab of rock were conducted to identify flow mechanisms occurring due to the presence of the isolated fracture. Two mechanisms occurred: (1) localized flow through the rock matrix in the vicinity of the isolated fracture and (2) pooling of water at the bottom of the fracture, indicating the occurrence of film flow along the isolated fracture wall. These mechanisms were observed at fracture angles of 20 and 60 degrees from the horizontal, but not at 90 degrees. Pooling along the bottom of the fracture was observed over a wider range of input fluxes for low‐angled isolated fractures compared to high‐angled ones. Measurements of matrix water pressures in the samples with the 20 and 60 degree fractures also demonstrated that preferential flow occurred through the matrix in the fracture vicinity, where higher pressures occurred in the regions where faster flow was observed in the visualization experiments. The pooling length at the terminus of a 20 degree isolated fracture was measured as a function of input flux. Calculations of the film flow rate along the fracture were made using these measurements and indicated that up to 22% of the flow occurred as film flow. These experiments, apparently the first to consider isolated fractures, demonstrate that such features can accelerate flow through the unsaturated zone and should be considered when developing conceptual models.
A new mineral, chrisstanleyite, Ag2Pd3Se4, from Hope's Nose, Torquay, Devon, England

Abstract Chrisstanleyite, Ag2Pd3Se4, is a new mineral from gold-bearing carbonate veins in Middle Devonian limestones at Hope's Nose, Torquay, Devon, England. It is associated with palladian and argentian gold, fischesserite, clausthalite, eucairite, tiemannite, umangite, a Pd arsenide-antimonide (possibly mertieite II), cerussite, calcite and bromian chlorargyrite. Also present in the assemblage is a phase similar to oosterboschite, and two unknown minerals with the compositions, PdSe2 and HgPd2Se3. Chrisstanleyite occurs as composite grains of anhedral crystals ranging from a few lam to several hundred μm in size. It is opaque, has a metallic lustre and a black streak, VHN100 ranges from 371-421, mean 395 kp/mm2 (15 indentations), roughly approximating to a Mohs hardness of 5. Dcalc = 8.308 g/cm3 for the ideal formula with Z = 2. In plane-polarised reflected light, the mineral is very slightly pleochroic from very light buff to slightly grey-green buff, is weakly bireflectant and has no internal reflections. Bireflectance is weak to moderate (higher in oil). Anisotropy is moderate and rotation tints vary from rose-brown to grey-green to pale bluish grey to dark steel-blue. Polysynthetic twinning is characteristic of the mineral. Reflectance spectra and colour values are tabulated. Very little variation was noted in eleven electron-microprobe analyses on five grains, the mean is: Ag 25.3, Cu 0.17, Pd 37.5, Se 36.4, total 99.37 wt. %. The empirical formula (on the basis of ∑M + Se = 9) is (Ag2.01Cu0.02)∑2.03 Pd3.02Se3. 95, ideally Ag2Pd3Se4 . Chrisstanleyite is monoclinic, a 6.350(6), b 10.387(4), c 5.683(3) Å, β 114.90(5)° space group P21/m (11) or P21(4). The five strongest X-ray powder-diffraction lines [d in Å (I)(hkl)] are: 2.742 (100) (-121), 2.688 (80) (-221), 2.367 (50) (140), 1.956 (100) (-321,150) and 1.829 (30) (-321,042). The name is in honour of Dr Chris J. Stanley of The Natural History Museum in London. The mineral and its name have been approved by the Commission on New Minerals and Mineral Names of the International Mineralogical Association.
Segmentation and object-oriented classification of wetlands in a karst Florida landscape using multi-season Landsat-7 ETM+ imagery

Segmentation and object-oriented processing of single-season and multi-season Landsat-7 Enhanced Thematic Mapper Plus (ETM+) data was utilized for the classification of wetlands in a 1560 km2 study area of north central Florida. This segmentation and object-oriented classification outperformed the traditional maximum likelihood algorithm (MLC) in accurately mapping wetlands, with overall accuracies of 90.2% (single-season imagery) and 90.8% (multi-season imagery), compared to overall accuracies for the MLC classifiers of 78.4 and 79.0%, respectively. Kappa coefficients were over 1.5-times greater for the segmentation/object-oriented classifications than for the MLC classifications, and producer and user accuracies were also higher. The producer accuracies of the segmentation/object-oriented classifications were 90.8% (single-season) and 91.6% (multi-season), compared to 70.6 and 74.4%, respectively, for the MLC classifications. User accuracies were 73.9 and 73.5% for the single-season and multi-season segmentation/object-oriented classifications, respectively, compared to 54.1% (single-season) and 55.0% (multi-season) for the MLC classifications. The use of multi-seasonal data resulted in only a slight increase in overall accuracy over the single-season imagery. This small increase was primarily due to better discrimination of riparian wetlands in the multi-season data. Segmentation and object-oriented processing provides a low-cost, high-accuracy method for classification of wetlands on a local, regional, or national basis.
The dependence of X band microwave sea return on atmospheric stability and sea state

The dependence of microwave sea retun at an incidence angle in the Bragg regime on wind speed, atmospheric stability, dominant wave slope, and dominant wave frequency has been measured. The measurements were made from a tower in the Gulf of Mexico with a CW, X band microwave system operating at a 45° incidence angle. Measured microwave parameters were relative cross sections and ocean wave-radar modulation transfer functions obtained with antennas directed into wind and waves. The data reveal that cross sections increase with decreasing z/L (z being height and L being the Obukhov length) in unstable atmospheric conditions. The rate of increase is much higher than that of surface stress calculated on the basis of present boundary layer models. Furthermore, these data indicate that in near-neutrally stratified atmospheric conditions, X band cross sections at constant and relatively low wind speeds increase with long-wave slope, while modulation transfer functions decrease with long-wave slope. No clear dependence of either parameter on wave slope was observed in highly unstable conditions. The implications of these findings for other microwave frequencies and for scatterometry and microwave imagery of the sea are briefly discussed.
Continental-Scale Simulation of the Antarctic Katabatic Wind Regime

Abstract Katabatic winds are a common feature of the lower Antarctic atmosphere. Although these drainage flows are quite shallow, there is increasing evidence that the low-level circulations are an important component in establishing large-scale tropospheric motions in the high southern latitudes. Three-dimensional numerical simulations of the Antarctic katabatic wind regime and attendant tropospheric circulations have been conducted over the entire continent to depict the topographically forced drainage patterns in the near-surface layer of the atmosphere. Results of the simulation enable a mapping of katabatic wind potential and identification of coastal regions which may experience anomalously intense katabatic winds. A large upper-level cyclonic circulation forms rapidly in response to the evolving katabatic wind structure in the lower atmosphere, suggesting that the drainage circulations are an important component in prescribing the resulting resulting circumpolar vortex. These results imply that som.
Evaluation of Drainage from Passive Suction and Nonsuction Flux Meters in a Volcanic Clay Soil under Tropical Conditions

Root zone drainage measurements are needed to improve fertilizer management in areas where agriculture may be impacting groundwater supplies. We present results of field tests where drainage was measured with two types of suction (resolution of 0.16 and 1.6 mm tip−1) and a nonsuction (resolution of 0.22 mm tip−1) water flux meter (WFM). The soil was a microstructured weathered volcanic ash located on a coral atoll subject to intense rainfall and located in the Kingdom of Tonga. Our objectives were to evaluate water flux measurements by comparing them with (i) simple water balance estimates of cumulative fluxes, (ii) cumulative fluxes deduced from soil moisture content changes, and (iii) simulated fluxes using HYDRUS‐1D. Soil hydraulic properties were obtained at five soil depths. During the 60‐d evaluation period rainfall totaled 340 mm. The WFMs were installed in duplicate using disturbed soil. The consistency of the shape of the drainage curves measured with the WFMs, those derived from soil moisture changes, and those obtained with modeling led us to conclude that soil disturbance during WFM installation did not severely influence measurements. This was attributed to the strong microaggregation and disturbance introduced by plowing. Water balance and HYDRUS model estimates of drainage corresponded well with the measurement by nonsuction WFMs. Suction WFMs overestimated drainage, possibly due to flow convergence created by wick and divergence barrier lengths being not properly sized for the observed flow conditions. After the evaluation period some of the WFMs failed to respond. Nevertheless, flux meters are seen as promising tools to provide remote and continuous measurement of root zone drainage.
Campanile (Mollusca: Gastropoda): a new record from the early Miocene of Victoria, Australia

Campanile rupicolum sp. nov. is described from the early Miocene Upper Maude Limestone Member of Maude, Victoria. The genus has not hitherto been recorded from Victoria, a part of the Southeast Australian biogeographic Province, and was thought to be characteristic of the Austral-Indopacific Province. This is the oldest occurrence of the genus so far recorded from Australia.
Mesozoic magnetic lineations in the Bering Sea Marginal Basin

A compilation of marine magnetic profiles from the Bering Sea marginal basin has revealed the existence of north-south trending magnetic lineations over the deep abyssal basins. The anomalies in the Aleutian and Bowers basins have maximum peak to peak amplitudes of 350 γ and wavelengths characteristic of sea floor spreading anomalies (25–100 km). These lineations are as much as 600 km long. In contrast, linear trends within the Komandorsky Basin are less distinct and have anomalies with variable amplitudes. The magnetic anomalies along an 850-km profile crossing the Aleutian Basin have been correlated with the M1-M13 (117–132 m.y.) sequence of Larson's (1974) Mesozoic time scale. These anomalies increase in age from east to west and yield a half spreading rate of 5.1 cm/yr. North-south trending anomalies within Bowers Basin exhibit shapes and spacings similar to those from the Aleutian Basin, suggesting that these trends may have been connected at one time. Detailed model studies of the anomalies in the Aleutian Basin yield results which support the hypothesis that the igneous crust in the eastern Bering Sea is trapped oceanic plate which may have been part of the Mesozoic Pacific Basin. The model studies have indicated that (1) normalized magnetization intensities are comparable to those estimated for the Mesozoic Hawaiian Lineations in the Pacific, (2) the approximate phase angle of the observed anomalies (−10°±20°) would allow the magnetic lineations either to be formed at their present location or else to be formed at a more southerly site and then moved to their present location, and (3) the width of transitions between adjacent polarity intervals is relatively large (W ≥ 16 km) and may be related to a redistribution of the remanent magnetization within a deeply buried layer 2. The corrected depth to layer 2 is within 5% of the depth predicted for Mesozoic crust (120 m.y.) on the Sclater (1972) depth versus age curves. Although the north-south trending anomalies in the Aleutian and Bowers basins are interpreted as sea floor spreading anomalies, the origin of the anomaly pattern in the Komandorsky Basin is not understood.
Multi-year water and surface energy budget of a high-latitude polythermal glacier: evidence for overwinter water storage in a dynamic subglacial reservoir

Abstract This paper examines the water budget and surface energy balance of a Svalbard glacier (midre Lovénbreen) over a 6 year period (1997–2002). Fresh-water yields are found to lie between 1.1 and 1.5 m a–1 and reflect variable amounts of glacier ice ablation (0.27 ± 0.15 ma–1) and more consistent amounts of snowmelt and summer precipitation (0.40± 0.10 and 0.49 ± 0.12 m respectively). Between 24% and 36% of the annual runoff is thought to pass through a subglacial drainage system. Although the site is heavily influenced by stable maritime air masses during the summer, surface melting is achieved largely by net shortwave radiation fluxes (74–100% of ablation). Water budget analysis shows that the annual runoff yields may be strongly influenced by water storage within the glacial system. Storage can occur over the winter period and force the early development of the subglacial drainage system during the following summer. Thus annual water fluxes from this glacier cannot be estimated from glacial mass-balance data alone and there is a need to assess the implications of overwinter storage for our understanding of glacial dynamics, annual fluvial process rates and mixing processes in Svalbard’s fjords.
Site S-7 Representative Model and Application for the Vadose Zone Monitoring System (VZMS) McClellan AFB - 1998 Semi-Annual Report

Vadose zone data collection and enhanced data analysis are continuing for the Vadose Zone Monitoring System (VZMS) installed at site S-7 in IC 34 at McClellan MB. Data from core samples from boreholes drilled in 1998 and from VZMS continuous monitoring are evaluated and compared to previously collected data and analyses. The suite of data collected to date is used to develop and constrain a spatially averaged, one-dimensional site S-7 representative model that is implemented into T2VOC. Testing of the conceptual model under conditions of recharge of 100 mm/yr produces plausible moisture contents relative to data from several sources. Further scoping calculations involving gas-phase TCE transport in the representative model were undertaken. We investigate the role of recharge on TCE transport as well as the role of ion- and gas-phase flow driven by density and barometric pumping effects. This report provides the first example of the application of the site S-7 representative model in th e investigation of subsurface VOC movement.
Temporal evolution of a magmatic dike system inferred from the complex frequencies of very long period seismic signals

[1] I present a detailed description of temporal variations in the complex frequencies of very long period (VLP) events observed in association with an earthquake swarm that occurred beneath Hachijo Island, Japan. The individual VLP signals show simple, decaying, harmonic oscillations with periods near 10 s, and they last for about 300 s. The VLP activity began on 20 August 2002 and continued until 2 April 2003. Spectral analysis of the VLP waveforms identifies two spectral peaks, of which the complex frequencies show systematic temporal variations at the beginning of the VLP activity. The Q values of both the peaks show increasing trends from roughly 15 to 35 in the time period between 22 and 26 August. The frequency of one peak shows a decreasing trend from 0.1 to 0.09 Hz, while the frequency of the other peak shows an increasing trend from 0.128 to 0.136 Hz during this time. After these systematic variations, the frequencies and Q values of the two peaks remain roughly constant. Waveform simulations based on a fluid-filled crack model indicate that the observed systematic temporal variations can be reasonably explained by gradual expansion of a crack containing a basalt-gas mixture. The roughly constant frequencies and Q values of the two peaks after these systematic variations suggest that the magmatic dike persistently existed beneath Hachijo Island for more than 6 months. Mass and heat advection is required to sustain the dike system, implying magmatic flow and convection in the dike and magma chamber beneath this island.