Miracle-dz/UniFAR-FTUs huggingface dataset:
Can relative paleointensities be determined from the normalized magnetization of the wind-blown loess of China?

Although the wind-blown loess and interbedded paleosol sequence in the Loess Plateau of China has been extensively studied and regarded as one of the most complete terrestrial records of both the geomagnetic field and climatic changes during the Quaternary, little attention has been paid to it as a source of relative paleointensity. In this study, we examine the Malan loess (L1), the last glacial sediments, in the Lingtai section to determine whether loess is able to reliably record the relative paleointensity. Toward that end both the conventional normalizing method as well as the pseudo-Thellier method [Tauxe et al., 1995] were used in conjunction with the examination of the rock magnetic properties and natural remanent magnetization (NRM). Rock magnetic properties of L1 show the uniformity in terms of magnetic mineralogy and grain size, suggesting that they may be suitable for relative paleointensity studies. Normalized remanences derived from L1 show highs between both 72-66 ka and 62-51 ka and lows near 63 ka, 42 ka and between 20 and 10 ka. Comparable results using different normalization parameters suggest that large-amplitude variation of normalized magnetization may reflect the intensity variation of the geomagnetic field. However, comparisons of the normalized magnetization with contemporaneous marine records show some dissimilarities. In particular, the intensity low at 20-10 ka, corresponding to the last glacial maximum, is not compatible with the Sint-800 composite record. On the other hand, spectral coherence analyses of middle- and high-frequency components of the normalized magnetizations suggest some climatic influence. Thus this apparent discrepancy may be explained by climatic changes in the Loess Plateau and the resulting effect on the NRM
High‐resolution seismic traveltime tomography incorporating static corrections applied to a till‐covered bedrock environment

A major obstacle in tomographic inversion is near-surface velocity variations. Such shallow velocity variations need to be known and correctly accounted for to obtain images of deeper structures with high resolution and quality. Bedrock cover in many areas consists of unconsolidated sediments and glacial till. To handle the problems associated with this cover, we present a tomographic method that solves for the 3D velocity structure and receiver static corrections simultaneously. We test the method on first-arrival picks from deep seismic reflection data acquired in the mid- late to 1980s in the Siljan Ring area, central Sweden. To use this data set successfully, one needs to handle a number of problems, including time-varying, near-surface velocities from data recorded in winter and summer, several sources and receivers within each inversion cell, varying thickness of the cover layer in each inversion cell, and complex 3D geology. Simultaneous inversion for static corrections and velocity produces a much better image than standard tomography without statics. The velocity model from the simultaneous inversion is superior to the velocity model produced using refraction statics obtained from standard reflection seismic processing prior to inversion. Best results using the simultaneous inversion are obtained when the initial top velocity layer is set to the near-surface bedrock velocity rather than the velocity of the cover. The resulting static calculations may, in the future, be compared to refraction static corrections in standard reflection seismic processing. The preferred final model shows a good correlation with the mapped geology and the airborne magnetic map.
Venting from the Mid-Atlantic Ridge at 37°17′N: the Lucky Strike hydrothermal site

Abstract The Lucky Strike hydrothermal field on the Mid-Atlantic Ridge (MAR) at 37°17′N was discovered in 1992 during dredging operations carried out as part of the FARA Program (French-American Ridge Atlantic). The vent field at Lucky Strike lies in a depression between three cones that form the summit of an axial seamount. The summit rises 400 m above the rift valley floor to a water depth of 1570 m. Hydrothermal fluids stream from several vent complexes with exit temperatures up to 333°C. This paper presents the first observations of hydrothermal plumes in the water column over Lucky Strike, including anomalies in light scattering with a nephelometer and dissolved Mn with the zero-angle photon fibre optic spectrometer. Plumes at Lucky Strike are small compared with those at other MAR hydrothermal sites such as TAG (26°N) and MARK (23°N). These small plumes are consistent with the relatively low Fe and Mn concentrations found in associated vent waters. The Sr/Ca ratios of these fluids are low, suggesting that the basaltic substrate below Lucky Strike is highly altered, but rare earth element concentrations are also low, indicating reduced mobilization. These observations together with the low fluid temperatures are suggestive of an old and waning hydrothermal system with extensive zones of subfloor alteration.
Climate and year‐to‐year variability of atmospheric and terrestrial water cycles in the three great Siberian rivers

Among all the rivers that flow into the Arctic Ocean, the Lena, Yenisei, and Ob are the three largest in terms of water discharge (R), and they are a large source of freshwater. We analyzed the R observed at the river mouths and precipitation minus evapotranspiration (P − E) estimated from atmospheric reanalyses. P is a key player in the water cycles of the Siberian rivers, but regional differences of E also affect the long‐term means of R and P − E. Climate fields and terrestrial conditions play some roles for the regional differences of P and E. A decomposition analysis of the moisture flux revealed that moisture transport associated with cyclone activity dominates the climatological features of P − E over the Lena, whereas moisture transport associated with seasonal mean winds dominates the features of P − E over the Ob. Both transport processes affect over the Yenisei. Whereas the moisture transports related to the climatological P − E differs among the rivers, P − E variations are mainly affected by the stationary component of moisture transport for all three Siberian rivers. Although previous studies have shown considerable deviations between P − E and R variations, the year to year variations agree very well with each other when appropriate seasonal time lags are taken into account. Comparison with the results of six atmospheric reanalyses indicated that estimations of P − E with the reanalyses produce values comparable to observed Rs and are therefore an effective way to examine the water cycles of the Siberian rivers.
The ecology of Lower Cambrian buildups from Zuune Arts, Mongolia: implications for early metazoan reef evolution

Reefal buildups in western Mongolia of mid-Early Cambrian (late Atdabanian) age flourished during a period when shelf seas were globally widespread. The succession at Zuune Arts records the transition from shallow marine siliciclastic sediments (Bayan Gol Formation) to shallow marine, but still clastic-influenced, carbonates (Salaany Gol Formation). The Salaany Gol Formation is interpreted as having been deposited as a series of shallowing upwards cycles on a shallow, gently inclined shelf in a rapidly subsiding epicontinental sea. Cycles commenced with the growth of subtidal metazoan-calcimicrobe aggregative communities on an open shelf. The resultant buildups were commonly engulfed by extensive, massive microbial stromatolites when they grew in agitated intertidal conditions. Latterly, they were smothered by ooid shoals in response to rapid sea level rise. Four types of reefal buildup are distinguished: (1) green-coloured calcimicrobe (Tarthinia, Epiphyton, Gordonophyton and Renalcis) boundstones; (2) red-or green-coloured Cambrocyathellus-Tarthinia-Epiphyton bafflestones; (3) red-coloured Okulitchicyathus bindstones; and (4) red-coloured radiocyath-archaeocyath-cribricyath bioherms. Each is interpreted as having grown at increasing depths and possibly sedimentation rates. The buildups are commonly enclosed within graded and planar bedded bioclastic grainstones and packstones, and are best developed towards the top of the formation, when sea level was high. Thickets of large, solitary archaeocyaths are also inferred in the deeper interbiohermal areas. These buildups had synoptic relief and constructed porous structures with growth-framework cavities housing diverse coelobiontic communities. Extensive synsedimentary cements are present, including pseudomorphed aragonitic fans and possible pseudomorphed aragontic botryoids. These early reefs thus have geological fabrics similar to later Phanerozoic representatives. It is proposed however, that this ecosystem was largely composed of generalist and opportunistic filter and suspension feeders which were dependent upon a far higher input of nutrients than modern day reefal developments. Bacteria were probably the main primary producers, from both planktic and benthic cyanobacterial communities. The diversity of each buildup assemblage appears to be controlled by primary cavity size, the richest fauna belonging to the highly tiered radiocyath-dominated community inferred to have lived in the deepest waters. The communities at Zuune Arts can be compared with other buildups from the early Cambrian, and with Lower Ordovician receptaculid-calcimicrobe-solitary sponge bioherms known from the USA and Siberia.
Propagating versus Nonpropagating Madden–Julian Oscillation Events

AbstractBasinwide convective anomalies over the Indian Ocean (IO) associated with the Madden–Julian oscillation (MJO) sometimes propagate eastward and reach the west Pacific (WP), but sometimes do not. Long-term observations and reanalysis products are used to investigate the difference between the propagating and nonpropagating MJO events. IO convection onset events associated with the MJO are grouped into three categories based on the strengths of the simultaneous dry anomalies over the eastern Maritime Continent and WP. The IO convection anomaly preferentially makes eastward propagation and reaches the WP when the dry anomaly is stronger.Analysis of the column-integrated moist static energy (MSE) budget shows that horizontal advection moistens the atmosphere to the east of the positive MSE anomaly associated with the active convection over the IO and is of sufficient magnitude to explain the eastward propagation of the positive MSE anomaly. Interpretation is complicated, however, by lack of closure in .
The death of the West : how dying populations and immigrant invasions imperil our country and civilization

The national bestseller that shocked the nation--"The Death of the West" is an unflinching look at the increasing decline in Western culture and power.The West is dying. Collapsing birth rates in Europe and the U. S. , coupled with population explosions in Africa, Asia and Latin America are set to cause cataclysmic shifts in world power, as unchecked immigration swamps and polarizes every Western society and nation. "The Death of the West "details how a civilization, culture, and moral order are passing away and foresees a new world order that has terrifying implications for our freedom, our faith, and the preeminence of American democracy. "The Death of the West" is a timely, provocative study that asks the question that quietly troubles millions: Is the America we grew up in gone forever?
Kinematic and thermal constraints on the reactivation of the Outer Hebrides Fault Zone, NW Scotland

Abstract The Outer Hebrides Fault Zone is a major easterly dipping reactivated shear zone which displaces Lewisian gneiss of the Laurentian craton, NW Scotland. Despite a number of detailed field studies, the fault zone remains poorly understood with regard to both its age of inception and precise conditions of reactivation. The island of Scalpay in the northern portion of the Outer Hebrides Fault Zone provides exceptional exposures through a variety of reactivated fault rock types and therefore represents an ideal location to investigate fault zone evolution via fluid inclusion studies of syn-tectonic quartz veins. This fluid inclusion study constrains reactivation temperatures more precisely than hitherto possible with top-to-the-NW ductile thrusting occurring at 500 ± 30°C. Subsequent phyllonitization is associated with oblique sinistral top-to-the-NE strike-slip at 230 ± 20°C, followed by a discrete system of top-to-the-NE/SE extensional detachments at 150 ± 20°C. Other recent fluid inclusion studies in the southern portion of the Outer Hebrides Fault Zone constrain phyllonitization associated with top-to-the-E displacement to 370 ± 20°C, with subsequent top-to-the-NE extensional detachments operating at 150–210°C. Thus, late-stage extensional detachment systems record consistent conditions of reactivation along the strike length of the Outer Hebrides Fault Zone. However, our results also clearly emphasize that conditions of earlier fault zone reactivation and phyllonitization were highly heterogeneous between the northern and southern portions, thus suggesting a spatial and temporal variation in the deformation and/or fluid flux system.
How things began: the origins of geological conservation

Abstract The origins of geoconservation cannot be investigated without first defining its scope. This presents a problem because there is no established working definition of the field. By using the Giant's Causeway as a case study, useful parameters were identified revealing great complexity. They embrace initial curiosity, scientific communication, mythology, access issues, the involvement of national scientific institutions, controversial but ultimately successful iconography, the invention of new artistic conventions, dissemination by engraving, scientific reaction, rekindling of a fundamental geological controversy, tourism, popular literature, modes of transport, commercialization, additions to fundamental science, designation history and historic associations of the site. Other sites are similarly complex and assist in refining the scope. Sites are seen as the principal resource but on analysis achieve their status from what they reveal or the importance of the materials they yield, in turn spotlighting the major museum collections. These are now well documented though not all are secure. It was not the scientific imperative that established the first public designation but an impassioned delight in unspoiled nature which three men, two Americans, Henry Thoreau and George Marsh but especially the Scots environmentalist, John Muir, projected carefully into the attuned ear of the US President. This brief overview closes with the revelation of neglected areas of heritage, paths that geoconservation could have taken and still may and suggests how earlier definitions could be elevated into a more specific and holistic geoconservation strategy.
The electrical field in a borehole with a casing

The electric field on the borehole axis in the presence of a casing can be divided into three zones: the near, intermediate, and far zones. Within the intermediate zone, determination of the second derivative of the potential allows me to define the formation resistivity. Outside the casing, the electric field, at large distances from the borehole, has a radial direction that provides a sufficient depth of investigation in this direction. The measurement requires knowledge of the casing conductance. Application of transmission line theory is based on the fact that the electric field in the formation is radial within the intermediate zone, resulting in the conclusion that the vertical resolution of such a measurement would depend only upon the spacing of the electrodes required to estimate the second derivative of the potential.
Forecast Skill of Madden-Julian Oscillation Events in a Global Nonhydrostatic Model during the CINDY2011/DYNAMO Observation Period

Near real-time week-long forecasts of Madden-Julian Oscillation (MJO) events using a regionally stretched global nonhydrostatic model were executed for the intensive observation period of the Cooperative Indian Ocean experiment on intraseasonal variability in the year 2011 (CINDY2011)/Dynamics of the MaddenJulian Oscillation (DYNAMO) field program. Forecast skill was validated using a real-time multivariate MJO (RMM) index and the forecast skill scores. The scores indicated a dependency on the initial MJO amplitude and phase. The errors were smaller in forecasts initialized in the active period of the MJO. A tendency for over-amplification (under-amplification) in forecasts initialized at phases 2−6 (7−8, 1) and earlier (delayed) phase propagation in the forecasts initialized at phases 1−3 (5−6) was identified. This was related to systematic positive biases in RMM1 and RMM2. The RMM1 error dominated in wind fields without significant contributions from convection. The RMM2 error grew in both convection and wind anomalies after the 5-day lead time, causing reduction in the MJO skill score. These results suggest that improvement in the basic model fields, i.e., large-scale circulations and a link between convection and dynamics, should extend the predictability of MJO in this framework. (Citation: Nasuno, T., 2013: Forecast skill of Madden-Julian Oscillation events in a global nonhydrostatic model during the CINDY2011/DYNAMO observation period. SOLA, 9, 69−73, doi: 10.2151/sola.2013-016.)
The Optical Properties of Ice and Snow in the Arctic Basin

Abstract Measurements of light transmission and reflection were carried out on first-year sea ice near Point Barrow, Alaska, and on multi-year ice near Fletcher’s Ice Island in the Beaufort Sea (lat. 84° N., long. 77°W.). Spectral albedos (400-1 000 nm) and extinction coefficients (400-800 nm) were determined for melt ponds, snow, and various types of bare ice. Albedos were largest in the 400-600 nm range, decreasing toward longer wavelengths at a rate which appeared to be related to the liquid-water content of the near-surface layers. Extinction coefficients remained nearly constant between 400 and 550 nm, but increased rapidly above 600 nm. At 500 nm, albedos ranged from 0.25 over mature melt ponds to 0.93 over dense dry snow, while the corresponding extinction coefficients ranged from 0.6 to 16 m-1. Intensity profiles taken in the upper 50 cm of the ice indicated that the extinction coefficient at a particular wavelength was nearly constant with depth below 15 cm, although the bulk extinction coefficient decreased with depth because of the strong attenuation in the red. Near the surface it was found that multi-year ice absorbed slightly more energy than did first-year blue ice, but at depths below 10 cm the flux divergence in the first-year ice was three to four times larger than that in the multi-year ice. A simple procedure is described for estimating light transmission and absorption within the ice under clear or cloudy skies from total flux measurements at the surface. Methods by which satellite data could be used to estimate regional albedos, melt-pond fraction, and lead area are also presented.
Current state of Mediterranean water resources and future trends under climatic and anthropogenic changes

Abstract The Mediterranean basin has been identified as one of the world's regions most vulnerable to climatic and anthropogenic changes. A methodology accounting for the basin specific conditions is developed to assess the impacts of these changes on water resources. Based on global climate projections and water-use scenarios inspired by national reports, the current water stress state is addressed first and then it is explored for the medium-term. Currently, the southern and eastern rims are experiencing high to severe water stress. By the 2050 horizon, this stress could increase over the whole Mediterranean basin, notably because of a 30–50% decline in freshwater resources as a result of climate change. In addition, under a business-as-usual water-use scenario, total water withdrawals are projected to double on the southern and eastern rims. These worrying trends indicate the need to develop mitigation scenarios. In accord with the Mediterranean Strategy for Sustainable Development, an alternative water-use scenario based on improvements in the efficiency of water distribution networks and of irrigated agriculture is investigated. Such progress would stabilize total water withdrawals over the Mediterranean basin and even make them decrease (10–40%) in many northern catchments. Water stress could thus be tempered in some eastern catchments and remain low on the northern rim. This study highlights the importance of developing sustainable development strategies to cope with climatic and anthropogenic changes in order to explore their impacts at regional scales. It supports the need to focus on the most vulnerable areas within the Mediterranean basin. Editor Z.W. Kundzewicz Citation Milano, M. , Ruelland, D. , Fernandez, S. , Dezetter, A. , Fabre, J., Servat, E. , Fritsch, J.-M. , Ardoin-Bardin, S. , and Thivet, G. , 2013. Current state of Mediterranean water resources and future trends under climatic and anthropogenic changes. Hydrological Sciences Journal, 58 (3), 498–518.
Impact of the North Atlantic Oscillation on the trans-Atlantic migrations of the European eel (Anguilla anguilla)

Glass eel catches and FAO (Food and Agricultural Organization) landings of the European freshwater eel (Anguilla anguilla) show a decrease over the past 20 years. The long-term trends in the time series mask an interannual fluctuation, which becomes apparent on the application of a high-pass filter and autocorrelation analysis. Both the FAO landings and the glass eel catches show interannual fluctuations with a repeat period of 6–8 years, similar to the period of the North Atlantic Oscillation (NAO). Most glass eel catch monitoring stations are in phase. The glass eel catches show a significant negative correlation with the NAO lagged by 0–2 years, consistent with the hypothesis that the positive NAO phase has an adverse impact on the larval survival in and migration from the Sargasso Sea spawning location, one year prior to the arrival of the glass eels in Europe and North Africa. The FAO landings can be divided into two groups of different phase that have an approximate correspondence to the NAO dipole in winter rainfall in Europe and North Africa. One group (P) comprises Denmark, Ireland, Morocco, Netherlands, Norway, Sweden, Tunisia, and the United Kingdom, and the other group (N) comprises France, Germany, Italy, Poland, Portugal, Spain, and Turkey. At least for the interannual fluctuations, the success of the glass eel fishery (and eel recruitment) may be coupled with the number of migrating silver eels from the N group of countries and uncoupled with the P group of countries.