Miracle-dz/UniFAR-FTUs huggingface dataset:
Holothurian faunal changes at the Triassic-Jurassic boundary

The diversity pattern of holothurian echinoderms during the late Triassic-early Jurassic is quantitatively analysed to examine the effect of different taxonomic approaches. Whereas sclerite morphospecies indicate major faunal change during the Norian with significant extinction in the Upper Norian. changes are less pronounced for parafamilies and least for biologically based groups. Perceived diversity patterns are subject to bias. including a significant effect of relative research effort on morphospecies and parafamily data. A large proportion of Lazarus taxa in the Rhaetian-Hettangian indicates a sampling problem due to preservational or geographic bias. *Holothurian. Norian, Rhaetian, Hettangian, taxonomic diversity, origination, extinction.
Spectral finite element approach to postseismic deformation in a viscoelastic self-gravitating spherical Earth

SUMMARY Theoretical models of the viscoelastic relaxation of a spherical Earth are derived to model large-scale postseismic deformation resulting from great earthquakes (M > 7) over decadal timescales. Most existing models of postseismic deformation do not consider strong lateral heterogeneities in mantle viscosity, in particular in the subducting slab where such events occur. In addition, the self-gravitation effect is often treated only approximately. Both effects become important when observations from space geodetic techniques such as GPS and GRACE are interpreted. In this paper, we present a spectral finite-element approach that allows these two effects to be considered in a rigorous way. In this way, much larger lateral viscosity variations can be handled than by perturbation techniques. We derive interface conditions for an arbitrary shear fault in the form of double-couple forces that are equivalent to a prescribed dislocation and simulate a relaxation process for an incompressible Maxwell earth with a 3-D viscoelastic structure. Computational results are validated for a spherically symmetric model by an independent method based on the inverse Laplace integration, and good agreement is obtained. As an example, we apply this approach to the 2004 Sumatra–Andaman earthquake and simulate a large-scale postseismic gravity potential variation by a forward calculation. In the presence of a slab, the secular variation in geoid height change decreases by 30 per cent for wavelengths longer than 500 km, with respect to the case excluding the slab. The effect of the slab can exceed 0.3 mm yr −1 for short-term variations when the asthenosphere viscosity is 10 19 Pa s, which are larger than the observation errors of GRACE. For a displacement field, a decrease in deformation rates can amount to 70 per cent due to the inclusion of a slab, which is detectable with geodetic observations such as GPS. The effect of the slab is attenuated in the gravity field for such longer wavelengths since horizontal scales of the slab are smaller than its spatial resolution. Lateral heterogeneities in viscosity due to a slab should therefore be considered for interpreting observed postseismic relaxation due to a large thrust event in a subduction zone.
Crustal structure of the Caribbean–northeastern South America arc‐continent collision zone

[1] We present the results of a 568-km-long regional wide-angle seismic profile conducted in the southeastern Caribbean that crosses an active island arc, a remnant arc, two basins possibly floored by oceanic crust, an allochthonous terrane of forearc affinity, and the passive margin of northern South America. The velocity structures of the Late Cretaceous Aves Ridge remnant arc and Miocene and younger Lesser Antilles arc are remarkably similar, which implies that magmatic processes have remained moderately steady over time. Crustal thickness is ∼26 km at the Aves Ridge and ∼24 km at the Lesser Antilles arc. In comparison to the Izu-Bonin and Aleutian arcs, the Lesser Antilles arc is thinner and has no evidence for a lower crustal cumulate layer, which is consistent with the estimated low magma production rates of the Lesser Antilles arc. Crustal thickness beneath the Grenada and Tobago basins is 4–10 km, and the velocity structure suggests that these basins could be floored by oceanic crust. A decrease of ∼1 km/s in average seismic velocity of the upper crust is observed from NW to SE across the North Coast fault zone; we argue that this marks the suture between the far-traveled Caribbean arc and the passive margin of the South American continent. Current strike-slip motion between the Caribbean and South American plates is located ∼30 km to the south, and thus material originally deposited on the South American passive margin has now been transferred to the Caribbean plate.
Three essays on weather and crop yield

The general theme of this dissertation is the study of impacts of weather variability on crop yields, with each chapter addressing a specific topic related to this theme. Chapter 2 tests the hypothesis that corn and soybeans have become more drought tolerant by regressing county yields on a drought index and time. Results indicate that corn yield losses from drought of a given severity, whether measured in quantity terms or as a percentage of mean yields, have decreased over time. Soybean percentage yield losses have also declined but absolute losses have remained largely constant. The potential impact of increased drought tolerance on U.S. crop insurance rates is illustrated by comparing Group Risk Plan (GRP) premium rates assuming time-invariant susceptibility to drought with rates generated from regression results in this dissertation. Chapter 3 develops a linear spline model with endogenous knots to capture the non-linear impacts of rainfall and temperature on corn yields. A hierarchical structure is applied to capture the county-specific factors determining corn yields. Using Bayesian techniques, the thresholds and other model parameters are simultaneously estimated. Gibbs sampling and the Metropolis - Hastings algorithm are applied to estimate the posterior distributions. Corn yield decreases significantly above the upper temperature threshold and below the lower rainfall threshold. Results indicate a geographically clustering pattern of how corn yields respond to changes in temperature and rainfall. Chapter 4 applies the linear spline yield model developed in chapter 3 to examine weather impacts on yield trend, yield risk, and the distribution of corn yield. The climate trend from 1980 to 2009 explains up to 20% of observed yield trend. Not controlling for temporal weather patters leads to biased trend estimates, especially for short times series. Isolating changes in weather variability in the sample period, the hypothesis of constant coefficient of variation is rejected in most states in the Corn Belt. Decreasing marginal benefit of weather partly explains why corn yield is negatively skewed. Conditional on weather, the distribution of unexplained residuals from our yield model is symmetric in general.
A synchronous Alpine and Corsica-Sardinia rotation

[1] We report on the paleomagnetism of 34 sites from lower Oligocene–middle Miocene sediments exposed in the Tertiary Piedmont Basin (TPB, northern Italy). The TPB is formed by a thick (∼4000 m) and virtually undeformed sedimentary succession unconformably lying upon Alpine nappes decapitated by extensional exhumation, which in turn are tectonically stacked over the Adriatic foreland. Paleomagnetic directions from 23 (mostly Oligocene) sites were chronologically framed using new biostratigraphic evidence from calcareous nannoplankton. Our data, along with published paleomagnetic results, show that the TPB rotated ∼50° counterclockwise with respect to Africa in Aquitanian-Serravallian times. The rotation was likely driven by underneath nappe stacking and was synchronous with (further) bending of the Alpine chain. Both the rotation magnitude and its timing are similar to those documented for the Corsica-Sardinia microplate. Therefore the formation of the western Alpine arc (or at least part of its present-day curvature) occurred during the rollback of the Apenninic slab and related back-arc spreading of the Liguro-Provencal Basin and drift of the Corsica-Sardinia block. This suggests a common dynamics driving both the Alpine and the Apennine slab motions. Paleomagnetic data also document that the Adriatic plate has undergone no paleomagnetic rotation since mid-late Miocene times. Anisotropy of magnetic susceptibility data suggests that the TPB, an enigmatic basin arising from a controversial tectonic setting, formed in an extensional regime characterized by a stretching direction approximately orthogonal to the main trend of the underlying chain.
A Dendroclimatic Reconstruction of Annual Precipitation on the Western Canadian Prairies since A.D. 1505 from Pinus flexilis James

Abstract Tree-ring chronologies from living and sub-fossil Pinus flexilis James (limber pine) trees extend back more than 500 yr on the western edge of the Great Plains in Alberta. Living trees were found to be as old as 526 yr. Tree-ring growth in Pinus flexilis is most sensitive to annual precipitation over the annualization period August to July. The longevity of the trees coupled with their sensitivity to variations in annual precipitation make them an important resource for constructing annually resolved multicentury records of paleohydrology on the northwestern Great Plains. A 487-yr reconstruction of annual precipitation in southwestern Alberta was produced from the tree-ring series. This is the longest dendroclimatological reconstruction of precipitation available from the northern plains. The reconstruction has some similarity to reconstructions from the western Great Plains of the United States. However, there are also many divergences in the timing of droughts. Some of this divergence may reflect the importance of orographic uplift in producing precipitation along the eastern flanks of the Rocky Mountains. Our reconstruction shows that the frequency of droughts in Alberta during the period of instrumental records, about the last 100 yr, has not been appreciably different from conditions of the preceding four centuries. In addition, the most severe drought of this century, which led to widespread farm abandonment between 1918 and 1922, was not the most severe drought in the past 487 yr.
Australodelphis mirus, a bizarre new toothless ziphiid-like fossil dolphin (Cetacea: Delphinidae) from the Pliocene of Vestfold Hills, East Antarctica

Australodelphis mirus (Delphinidae n. gen., n. sp) is a small extinct Early Pliocene dolphin known from five individuals from shallow-water strata of the Sørsdal Formation, Vestfold Hills, East Antarctica. Australodelphis mirus is the first higher vertebrate named from the Oligocene-Pleistocene interval on land in Antarctica, and is the first cetacean fossil from the polar margin of circum-Antarctic Southern Ocean that postdates the break-up of Gondwana. The dolphin is convergent in skull form with some living beaked whales (Mesoplodon spp.; Family Ziphiidae) in its long, narrow and toothless upper jaw and face, but skull suture patterns, basicranial sinuses, and ear-bones indicate close relationship with living long-beaked dolphins (Delphinidae). Australodelphis mirus perhaps was a suction-feeding squid-eater which occupied quiet near-shore shelf waters influenced by glaciers but probably lacking major sea-ice. Possible ecological equivalents of A. mirus (small ziphiids, long-beaked dolphins) do not occupy Antarctic waters today, perhaps excluded by cold conditions and/or sea-ice cover. Earlier Pliocene cetaceans worldwide reveal significant extinct and sometimes bizarre taxa, and extant families with ranges quite different from today, pointing to climate-related changes in cetacean ecology in the last 2–3 million years.
Eastern equatorial Pacific response to three composite westerly wind types

It has been suggested recently that episodes of westerly wind near the international date line in the western Pacific tend to fall into one of four types. Three of the types have enough equatorial zonal wind variation to be able to induce an eastern Pacific response by forcing equatorial waves. In this note we examine the central and eastern Pacific waveguide response to idealized representations of these three types of westerly wind episodes, using a combination of linear theory and results from an ocean general circulation model. The idealized westerly wind types are the C type (maximum anomalies centered on the equator), the N type (maximum anomalies just north of the equator), and the S type (maximum anomalies just south of the equator). The composite C-type event excites equatorially trapped Kelvin pulses that alter sea surface temperature in the central and eastern Pacific. Warm anomalies caused by the C-type episode have approximately equal contributions from a zonal advection of heat by the Kelvin pulses and a meridional advection of heat by an altered instability wave field. Because the center of forcing of the S-type event is displaced off of the equator, the Kelvin pulses excited by the S-type episode have smaller amplitude than those of the C-type episode, even though the maximum wind anomaly is the same in the two cases. The S-type anomaly also excites weak Rossby-gravity waves that can propagate into the eastern Pacific. Because the Rossby-gravity waves are dispersive, their amplitude diminishes as the waves propagate into the eastern Pacific. The N-type episode, as observed in winds from the western tropical Pacific, is much weaker and of shorter duration than the C and S types, and therefore excites only a very weak eastern Pacific response. Although all types of westerly wind excite a local western Pacific response, only the C- and S-type events excite a significant eastern Pacific response.
A mechanism for the Venus thermospheric superrotation

A physical mechanism for in situ forcing of the Venus thermospheric superrotation is developed, which is in accord with the bulk of the constraining observations. Saturation of small- to medium-scale internal gravity waves in the thermosphere can supply the necessary accelerations of the mean flow if the waves have predominantly large westward phase speeds, characteristic of the wind speeds in the upper clouds. Several scenarios for wave forcing are examined, and the Lindzen-Holton parameterization is used to derive wave-induced accelerations of the mean flow. The results are compared to the VTGCM, which uses a similar wave drag parameterization with an ad hoc (empirically based) asymmetry parameter to model the superrotation.
Framework geophysical modelling of granitoid versus supracrustal basement to the northeast Thelon Basin around the Kiggavik uranium camp, Nunavut

The northeast Thelon Basin in the Kivalliq region of Nunavut is prospective for uranium deposits. Recently discovered basement-hosted, unconformity-associated prospects west of Kiggavik are restricted to deformed and metamorphosed Neoarchean psammitic enclaves of the Woodburn Lake group within 1.83 Ga Hudson granite and Martell syenite that together comprise the Shultz Lake intrusive complex (SLIC). The depth and geometry of the intrusive complex are relatively unknown as the geological constraints are poor; the drilling is sparse and of shallow depth extent as it was not targeting the basement but shallower multiply faulted and highly altered demagnetized zones. This study aims to constrain the geometry and context of the Shultz Lake intrusive complex with respect to the ore-hosting Neoarchean metasedimentary rocks and intersecting reactivated fault arrays through geophysical modelling of detailed aeromagnetic and gravity data integrated with new geological knowledge. By integrating detailed gravity, aer.
Estimation of Evapotranspiration from Bioretention Areas Using Weighing Lysimeters

In moving toward a water balance approach to storm water management and the modeling tools that can support such an approach, it is clear that there are substantial gaps in our knowledge of the groundwater recharge and evapotranspiration (ET) in urban areas. At a microscale, weighing lysimeters can be used to estimate the ET and may also be designed to also allow drainage (groundwater recharge) to be quantified. A weighing lysimeter has been designed and constructed in Guelph, Ont. to quantify the ET and groundwater recharge from a bioretention area. The results at this scale will vary with the urban surroundings, but will nevertheless contribute to the scant information available. The installation of similar systems in various urban micrometeorological conditions will help to build a database of urban ET and recharge. Other approaches, such as the eddy correlation approach for the ET, are also needed to complement microscale measurements.
Peer Reviewed: Recovering Sustainable Water from Wastewater

For water supplies to be sustainable, the rate at which water is withdrawn from water sources needs to be in balance with the rate of renewal or replenishment. At the same time, water quality must also be sustainable or recoverable. In nature precipitation replenishes surface water supplies and recharges groundwater. However, urbanization, agriculture, dams and reservoirs, and other shifts in land-use patterns are altering the rate, extent, and spatial distribution of freshwater consumption and replenishment. Therefore, water withdrawn for societal needs must also be considered a source in the sustainability equation.
Succession and stable isotope composition of gastropods in Holocene semi-arid alluvial sequences (Bardenas Reales, Ebro Basin, NE Spain): Palaeoenvironmental implications

Three alluvial units, ranging from the middle to late Holocene in age, were distinguished in Bardenas Reales Natural Park (Ebro Basin, NE Spain) based on morphosedimentary analysis and radiocarbon data. In this sensitive Mediterranean alluvial system, the succession and isotopic composition of gastropods greatly contribute to establishing the prevailing palaeoenvironmental conditions. The oldest unit (4763±87 to 2848±55 cal. yr BP) represents fluvial channels and swamped areas, includes the greatest proportion of aquatic gastropods (Ancylus fluviatilis and Lymnaea truncatula) and marsh species (Vallonia pulchella) and presents the most negative values of δ18O (mean −2.21‰ PDB). The intermediate unit (1403±60 to 836±65 cal. yr BP) shows a high rate of alluvial activity related to irregular torrential rainfall, with sedimentary features of aridity, and this unit includes only dry open ground gastropods (Xeroplexa sp., Chondrinidae indet. and Granopupa granum) and presents the least negative values of δ18O (mean −1.17‰ PDB). The youngest unit (191±97 to 127±82 cal. yr BP) exhibits a recurrence of flooding events, mostly includes marsh (Truncatellina callicratis and Lauria cylindracea) and aquatic (Lymnae truncatula) species and shows a very heterogeneous isotopic signal, with −1.83‰ PDB as the mean value of δ18O. As a consequence, a palaeoenvironmental pattern comprised of an early wetter/colder phase followed by a warmer/drier period and, finally, an increase in both cold conditions and hydrological variability, is deduced for the middle to late Holocene in the Ebro Basin. Gastropod shell δ13C values, related to vegetation, can also be linked to palaeoenvironmental changes. The succession and stable isotope composition of gastropods in alluvial sequences are revealed as very sensitive indicators of rapid Holocene climatic changes in fragile semi-arid landscape systems.
Radioactive contamination of milk and milk products in Japan.

Radioactive contamination of milk and milk products in Japan was studied extensively. Samples were collected monthly or every season from several districts of Japan.In this report, total radioactivity of raw milk and skim milk powder and strontium-90 (Sr-90) concentration of skim milk powder and sweetened condensed milk were measured. These experiments show that there is neither seasonal variation nor regional variation in total radioactivity, and that in the measurements of Sr-90 concentration the values in northern districts are higher than those in other parts of Japan.
Failure of a layer of buried surface hoar

In order to study the formation of the initial failure leading to dry‐snow slab avalanche release, we performed loading experiments in a cold laboratory with natural samples including a layer of buried surface hoar. The experimental setup was such that the layered snow samples were loaded continuously for various tilt (slope) angles; loading rates varied between 1 and 20 Pa s−1. The stress at fracture decreased with increasing loading rate and increasing slope angle, i.e., increasing shear component of the load. The latter result means that the layer was stronger in compression than in shear which is attributed to the particularly anisotropic nature of layers of buried surface hoar. Particle image velocimetry revealed that almost 90% of the sample's global deformation was concentrated in the weak layer. For avalanche release our results imply that the shear component of deformation is of particular importance for failure initiation.
First experiments in viewshed uncertainty : the accuracy of the viewshed area

Digital elevation models (DEMS) are computer representations of a portion of the land surface. The elevations recorded in the DEM are not, however, without error, and the United States Geological Survey (USGS) publish a root- mean-squared error (RMSE) for each Dm. The research reported here examines how that error propagates into derivative products resulting from geographic information system (GIS)-type operations. One product from a DEM, the focus of this paper, is the viewshed. The viewshed is the area observable from a viewing location versus that which is invisible. In this research repeated error fields with varying parameters are added to the original DEM, and the viewshed is determined in the resulting noisy DEM. Results show that the area of the viewshed calculated in the original DEM may significantly overestimate the viewshed area.
Note on the equations of Long waves over an uneven bottom

Equations for long waves in shallow water are derived systematically for an uneven bottom. With the basic assumption that the depth is small in comparison with a horizontal length scale, three regimes of approximation are presented according to the magnitude of the wave amplitude, (a) When the amplitude is of the same order of magnitude as the depth, the Airy equations are rederived as the first approximation, (b) When the amplitude is comparable to the cube of the depth, both lengths being nondimensionalized with respect to a common horizontal scale, two high-order nonlinear equations are obtained which include the classical cnoidal wave as a special solution for a horizontal bottom. These equations may be transformed to a set of first-order quasi-linear hyperbolic equations with the characteristic curves in the x-t plane directly related to the bottom profile. To facilitate numerical computations they are then written as differential equations along the characteristics. In the third regime (c) of extremely small wave amplitudes the appropriate linearized equations are given.