Miracle-dz/UniFAR-FTUs huggingface dataset:
Uplift of Oahu, Hawaii, during the past 500 k.y. as recorded by elevated reef deposits

Studies of paleo–sea level and past climate have focused upon proxy methods in ice and deep-sea cores and more direct information provided by past shorelines, in some cases preserved as raised or submerged reef deposits in tropical areas. Paleo-shorelines need to be constrained by accurate tectonic history because these environments and their marine deposits can be confused with past tsunami deposits and vice versa. A maximum 21-m-high extensive emerged reef on Oahu, Hawaii, U-series dated to 334 ± 17 ka, together with a mean U-series age of 335 ± 22 ka (n = 5) for slightly higher, energetic shoreline deposits nearby, suggest a marine isotope stage 9 (MIS 9) highstand, and extend the earlier work indicating a linear uplift for Oahu of 0.060 ± 0.001 mm/yr over the past 500 k.y. Five of the past six major emerged interglacial highstand reefs on Oahu have been identified, and these data provide little evidence for past maximum sea levels significantly greater than 2 m above the sea level datum at that time. There is currently no evidence for a MIS 11 highstand on Oahu.
Limiting conditions for cnoidal and Stokes waves

The second approximation to cnoidal waves is compared with the third approximation for Stokes waves of permanent form in water of finite depth. The comparison clearly indicates that cnoidal wave theory should not be applied to finite amplitude waves if their wavelengths are shorter than 5 times the depth. It is shown how the limiting heights of cnoidal waves are also related to the vanishing of the pressure gradient near the wave crest. The third approximation to Stokes waves in finite water depths is verified by the use of the classical small-perturbation expansion method which is best suited for small wave amplitudes. For finite amplitude waves the series expansion in terms of the infinitesimal-wave parameter is found to be most suitable for wavelengths shorter than 8 times the depth.
Formation of a metastable olivine wedge in a descending slab

We present a thermal model of a descending slab in which the transformation of olivine to spinel is controlled by pressure- and temperature-dependent reaction kinetics. Two different formulations of the kinetics are considered with the main discriminant being the temperature range over which olivine converts to spinel at pressures of about 15 GPa (about 500°–515°C and 560°–650°C). We use a finite element method to solve the coupled heat conduction (perpendicular and parallel to the dip of the slab) and kinetics equations, and we include the latent heat of the phase transformation. Latent heat release together with heat conduction parallel to the dip of the slab reduces significantly the length of the metastable olivine wedge and results in a very thin (≲5 km) two-phase region. We employ the thermal parameter υτ sin δ (υ is the velocity of the descending slab, τ is the age of the slab, and δ is the dip of the slab to the horizontal) to interpret the results for the length of the metastable wedge. For values of the thermal parameter smaller than about 4000 and 7000 km, depending on the model of the kinetics, no metastable olivine wedge exists (the critical value of 7000 km for the thermal parameter corresponds to the kinetics model with the lowest transition temperature range). The length of the metastable olivine wedge is also found to be very sensitive to the model of the kinetics and to the effects of adiabatic heating. If the occurrence of deep earthquakes is related to the transformation of metastable olivine to spinel, then data on earthquake depth versus thermal parameter require that the onset of the reaction takes place at temperatures of about 550°–575°C. In this case the slab thermal parameter must be larger than 10,000 km for the metastable olivine wedge to extend down to 660 km depth. But deep earthquakes occur near 660 km depth in slabs with thermal parameter as small as about 5000 km (South America, for example). Either some deep earthquakes are unrelated to olivine metastability or our knowledge of olivine-spinel reaction kinetics is incomplete.
How robust is the recent strengthening of the Tropical Pacific trade winds?

The persistent strengthening of the trade winds over the Pacific Ocean over the past 20 years has recently been proposed as a driver for the increase of ocean heat uptake linked to the hiatus in surface global warming. Crucial aspects in this argument are the reliability of the wind signal, usually derived from atmospheric reanalyses, and the ability of models to represent it. This study addresses these two aspects by comparing various observations with reanalyses and model integrations from the European Centre for Medium‐Range Weather Forecasts system. We show that the strengthening of trades over the Pacific is a robust feature in several observational data sets as well as in the reanalyses based on full and limited sets of observations. The wind trend is also reproduced in an atmospheric model integration forced by sea surface temperature analysis, a result that opens the doors to further investigation on the nature of the changes.
Hisslers: Quasi‐periodic VLF noise forms observed at low latitude ground station Jammu (L = 1.17)

This paper reports the observation of hisslers at a low latitude ground station Jammu (geomag. lat., 22°26′N), which are falling tone noises during the period of hiss activity and appear in minute‐long sequences with average spacing between individual bursts of the order of 0.2 seconds and falling tones do not overlap in time. Generation and propagation mechanisms are briefly discussed.
Rossby Normal Modes in Basins with Barriers

Abstract The Rossby wave, linear, normal modes for a barotropic fluid in a basin on the β plane are calculated in the presence of a thin barrier, which nearly divides the basin in two. Narrow gaps allow one subbasin to communicate to the other. In the case of a meridional barrier it is shown that the modes split into two categories: either full-basin modes, which have strong expression in both subbasins, or subbasin modes, which are limited to one or the other of the subbasins. The full-basin modes have natural frequencies very close to the eigenfrequencies of the basin in the absence of a barrier, while the subbasin modes oscillate at the eigenfrequencies of the subbasins as if they were isolated. In the former case, the oscillation is accompanied by strong flow through the gaps in the barrier while, in the latter case, there is essentially no flow through the barrier. If the barrier is opened by adding additional gaps, some of the modes turn from subbasin modes to full-basin modes. If the barrier is zon.
Power spectral analysis of auroral occurrence frequency

Power spectral analyses have been carried out on a data set of Swedish visual auroras for the period 1721 to 1943. Besides the anticipated 11-year, annual, and semiannual cycles, an unexpected peak near 1.4 years is found. The amplitude of this latter peak, while smaller than that of the 6-month and 12-month peaks, is statistically significant at between the 5% and 1% level and is found consistently in a sequence of spectra covering consecutive, overlapping, approximately 22-year data segments. The semiannual variation becomes extremely weak during the prolonged solar activity minimum at the beginning of the nineteenth century, and also shows some lessening during the prolonged solar activity minimum near the beginning of the twentieth century. The 1.4-year peak shows a strong modulation of about 65 to 68 years and an additional long-term trend of the order of centuries. The origin of this peak is unknown.
Physical modelling of deformations around piling augers in clay

Small-scale model tests are reported in which miniature augers were installed in beds of transparent synthetic soil simulating clay. As the auger advanced, the movement of reflective particles seeded into the soil and illuminated by laser light was recorded photographically. The displacement field in a vertical plane aligned with the auger axis was then determined using particle image velocimetry. The pattern of deformation of the soil around an auger of the type used to form a cast-in-situ screw pile was similar to that around a cylindrical straight-sided pushed pile. Deformations around an auger of the type used to form a rotary displacement pile depended on the rotation speed of the auger and the extent to which the flights carried soil upwards away from the tip. Lateral displacements in the model tests exhibited roughly similar trends to those observed in the field.
Melt ponds on sea ice in the Canadian Archipelago: 1. Variability in morphological and radiative properties

The morphological and radiative properties of melt ponds on first-year sea ice (FYI) were investigated during the summer of 1997 in the Canadian Archipelago as part of the Collaborative-Interdisciplinary Cryospheric Experiment (C-ICE) near Resolute Bay, Nunavut. In this paper we (1) describe a classification technique used to identify surface cover types from airborne videography during the melt pond season, (2) use the classification results to examine the fractional coverage of surface types and morphological characteristics of melt ponds, and (3) provide an estimate of the integrated shortwave albedo of this surface. Cluster analysis on the videography data identified four distinct surface cover types during the summer melt season: snow, saturated snow, light-colored melt ponds, and dark-colored melt ponds. Melt pond coverage was found to be highly variable over our study area. We found that pond sizes tended to be twice as large in areas of high melt pond density compared to ponds in areas of low pond density owing to their interconnective nature. Video data also identified an elongated melt pond morphology pattern over the smoothest FYI within our study region. A derived estimate of the integrated shortwave albedo was strongly related to the fractional cover of snow on the surface (R2 = 0.86). An analysis of combined fractional coverage of light and dark melt ponds from two aerial survey dates (Julian Days 181 and 184) revealed an aerial increase in melt ponds of ∼10.3%.
Normal fault geometry and fault reactivation in tectonic inversion experiments

Abstract Scaled physical models of extensional structures associated with fault reactivation were achieved in sand by superimposing extensional tectonics on thrust faults created during prior episodes of horizontal shortening. The extension produced three distinct responses: selective reactivation of pre-existing thrusts, favouring the steepest thrusts and those dipping more than a critical value; development of new normal faults that were linked to or developed within the zone of thrust faults; or generation of new normal faults in previously unfaulted domains. Linked normal faults showed a wide range of orientations and most dipped less steeply than the unlinked faults, which had dips clustered about the value predicted from the internal friction coefficient of sand. During extension of a distributed fault model, reactivation of existing thrusts influenced the location, dip direction, and dip magnitude of linked normal fualts. Compared to natural fault systems, the models showed many geometric similarities especially regarding linked normal faults.
Photosynthetic recovery of foliage after wind disturbance activates ecosystem CO2 uptake in cool temperate forests of northern Japan

[1] The effects of wind disturbance on forest dynamics and ecosystem CO2 exchange were examined in cool temperate forests of northern Japan during 2004–2008 using eddy covariance (EC) measurements. One site was a young, even-aged, monoculture, deciduous forest; the other was an uneven-aged mixed forest of evergreen and deciduous overstory tree species, including some over 200 years old. On 8 September 2004, a strong typhoon struck the forests, after which leaf and branch amounts decreased in young growth forest, but foliage showed little change in old growth forest. By 2006, foliage at the young-growth forest had recovered to the 2004 pretyphoon state. Average daily accumulated gross primary production (GPPd), terrestrial ecosystem respiration (TERd), and net ecosystem exchange (NEEd) were assessed for six growth stages annually. After the typhoon, large increases in GPPd were found during the growing stage of overstory tree species with high photosynthetic rates compared to that before the typhoon. Pronounced increases in GPPd and corresponding large reductions in NEEd were detected at the young-growth forest, indicating that NEEd was largely regulated by GPPd throughout the growing stages. Although EC measurements contain uncertainty, our continuous EC measurements revealed that interannual variability in meteorological variables and structural changes in foliage have only small impacts on GPP and NEE, while photosynthetic recovery of foliage from typhoon damage has high potential to increase GPP and enhance NEE as compared with those under nondamage conditions.
A global climatology of ionospheric irregularities derived from GPS radio occultation

GPS radio occultation measurements from CHAMP, GRACE‐A and FORMOSAT‐3/COSMIC are used to derive global information on small‐scale ionospheric irregularities such as sporadic E layers between January 2002 and December 2007. The investigations are based on the analysis of amplitude variations of the GPS radio occultation signals. The global distribution of ionospheric irregularities shows strong seasonal variations with highest occurrence rates during summer in the middle latitudes. The long‐term data set of CHAMP allows for first climatological studies, while the data coverage increases significantly with the combination of CHAMP, GRACE and FORMOSAT‐3/COSMIC measurements. This allows for global maps of sporadic E occurrence rates of very high spatial resolution where the influence of the Earth's magnetic field becomes visible in global sporadic E maps for the first time.
Are observed decadal changes in intermediate water masses a signature of anthropogenic climate change?

Recent observations have shown relatively large changes in the temperature and salinity of intermediate water masses in the ocean on decadal timescales. We compare the observed changes with simulations of the coupled climate model HadCM3. In simulations driven by anthropogenic forcing, we see significant changes in intermediate waters in the Southern Ocean which are similar in both pattern and magnitude to the observations. Our results suggest that the observed changes are most likely to be a signal of anthropogenic climate change. The strong signal in the Southern Ocean, which is detectable in the model from the 1980s, is in marked contrast with the intermediate waters of the Northern hemisphere oceans, where internal climate variability is large and a signal of anthropogenic climate change is not detectable in the model until 2020 at the earliest. Our results suggest that intermediate waters, particularly those of the Southern hemisphere, are a potentially sensitive indicator of anthropogenic climate change, and could be an important part of a climate monitoring network.
Climates of the British Isles : Present, Past and Future

Our understanding of climate and its role in human affairs has changed markedly over recent years, as have climate observation systems and modelling capabilities. Reliance on recent weather statistics to provide a guide for future climate is no longer viable. Evidence of human-induced climate change has placed climate high on political and the media agendas. Climates of the British Isles provides a comprehensive account of what we know about climate and changing climates at the end of the twentieth century. Integrating the historical and geographical dimensions of climate, the crucial link between past and future climatic conditions is examined through the geographical lens of the British Isles. Climates of past ages are reconstructed and full descriptions of present climate are illustrated by a wealth of graphs, maps and images. Important climate data sets are provided. Marking the twenty-fifth anniversary of the internationally acclaimed Climatic Research Unit, this book distils much of the leading research of present and recent members of the unit and presents an authoritative, accessible view of climatic change and prospects for the next millenium and beyond.
Calcitic, aragonitic and mixed calcitic-aragonitic ooids from the mid-Proterozoic Belt Supergroup, Montana

A great variety of ooid types occurs within the Siyeh and Snowslip Formations of the mid-Proterozoic Belt Supergroup, Montana. Cortical layers are inferred to have been composed either of calcite in a radial-concentric or radial-with-dark-rays fabric or, aragonite in a radial or concentric fabric. The calcitic cortical layers record their original fabrics but the originally aragonitic cortical layers have been replaced by calcite in a range of textures and by quartz and dolomite. Some formerly aragonitic cortical layers are replaced by calcite spar which contains relics of the original cortical structure. Others consist of calcite spar without inclusions, or columnar calcite which grew radially from the nucleus, commonly a calcitic ooid. Some ooids were wholly composed of calcite, others were of aragonite, but two phase ooids were common, mostly consisting of an inner calcitic part and an outer aragonitic part. Probable microdolomite inclusions suggest a high Mg content of the calcitic cortical layers. The depositional environment of these oolites was probably analogous to Baffin Bay, Texas, where a similar range of ooid types is forming today.
Effect of steeper Archean geothermal gradient on geochemistry of subduction-zone magmas

The comparative study of Archean and post-Archean granitic rocks shows significant changes with time. The high rare-earth element fractionation and the low Yb content of the Archean granitoids indicate the major role of garnet and hornblende, whereas these two minerals do not play a prominent part in the genesis of modern granitic rocks. This difference is a direct consequence of the cooling of Earth. In Archean time the subducted oceanic crust was young and warm, so it reached the conditions of melting before dehydration had occurred, leaving a garnet- and hornblende-bearing residue. In contrast, the modern subducted oceanic slab is generally old and cold, so it is dehydrated before it reaches the melting conditions of hydrous tholeiite; therefore, in the absence of a hydrous phase, it cannot melt at shallow depth. The fluids produced by dehydration reactions of modern crust rehydrate the overlying mantle wedge, which, in consequence, can undergo partial melting and give rise to calc-alkaline magmas; in this case, olivine and pyroxene are the most important residual phases. The location of calc-alkaline magma genesis in subduction-zone environments has migrated over time from the subducted Archean oceanic crust to the mantle wedge, a migration attributed to the progressive cooling of Earth.
Impact des activités humaines sur la dynamique littorale : prélèvements de sables sur le site de Pointe Sarène, Sénégal / Impact of sand extractions on coastal dynamics (Sarène Point beach, Senegal)

Resume Les extractions de sable constituent un facteur important de degradation du milieu littoral. Ces pratiques, liees a une forte demande en materiaux de construction, ont un impact negatif sur la dynamique cotiere. Si les extractions ne representent pas l'unique facteur responsable de l'erosion, elles constituent, en revanche, un facteur accelerant le recul de la cote. Elles engendrent une crise sedimentaire qui se traduit par l'epuisement progressif du stock de sable. Le cas de la plage de Pointe Sarene, sur la Petite Cote du Senegal, est tres representatif. Le budget sedimentaire de la plage de Pointe Sarene a ete quantifie et denote un bilan sedimentaire largement deficitaire de 211 000 m\an ', alors qu'il serait positif (116 000 m3.an ') en absence de prelevements de sable. Les extractions ont provoque, ces dernieres annees, un recul du trait de cote qui est estime a 15 m'. an1, alors qu'il etait negligeable lors de la periode 1974-1989. Ces extractions ne mettent pas uniquement en peril le secteur exploite, elles se repercutent egalement sur l'equilibre des plages situees a l'aval. En definitive, les extractions ont introduit des perturbations importantes en rompant l'equilibre du systeme cotier.
Knowledge gathering and communication on biodiversity: Developing the Norwegian Nature Index

The authors reflect on knowledge-generating and communication processes involved in the recently developed Norwegian Nature Index, particularly the communication process among experts involved in providing the required biodiversity knowledge. Eliciting a comprehensive overview of biodiversity is a complex process involving choices of approaches and methods in order to reach a common understanding of uncertainties and values as a basis for quantification. Part of the complexity is the establishment of dialogue between experts from research institutions with different research traditions and approaches. The authors discuss how the index was developed through communication processes, challenging involved experts to provide not only biodiversity data for the current situation, but also forecasts of future trends, assessments of uncertainty, and evaluations of the urgency of biodiversity loss and possibility of implementing policy and management measures. The Nature Index framework has potential for informing the biodiversity policy debate by involving stakeholders beyond the science-policy community and enhancing deliberations about biodiversity policy in a wider context of sustainable development. As a policy tool, the Nature Index may develop through a process of practical application, which in turn may have an impact on the selection of narratives, definition of management targets, and technical concepts such as reference states.
Estimating heterogeneous effects of continuous exposures using Bayesian tree ensembles: revisiting the impact of abortion rates on crime

In estimating the causal effect of a continuous exposure or treatment, it is important to control for all confounding factors. However, most existing methods require parametric specification for how control variables influence the outcome or generalized propensity score, and inference on treatment effects is usually sensitive to this choice. Additionally, it is often the goal to estimate how the treatment effect varies across observed units. To address this gap, we propose a semiparametric model using Bayesian tree ensembles for estimating the causal effect of a continuous treatment of exposure which (i) does not require a priori parametric specification of the influence of control variables, and (ii) allows for identification of effect modification by pre-specified moderators. The main parametric assumption we make is that the effect of the exposure on the outcome is linear, with the steepness of this relationship determined by a nonparametric function of the moderators, and we provide heuristics to diagnose the validity of this assumption. We apply our methods to revisit a 2001 study of how abortion rates affect incidence of crime.