InSAR surface deformation and numeric modeling unravel an active salt diapir in southern Romania

AbstractSalt diapirism is often associated with potential hydrocarbon energy resources, and detecting active diapirs can strongly affect the prospect to discover new gas and oilfields. Here we use InSAR techniques as a proxy to evaluate surface deformation in the Diapiric Fold Zone located in the East Carpathians Bend. Significant surface uplift (~ 5 mm/year) is identified in a relatively small region not previously known for the presence of an actively rising salt diapir. Using high-resolution two-dimensional thermomechanical numerical simulations of salt diapirs intrusions, we show that that the observed surface deformation can be induced by a relatively small salt diapir (1–2 km in diameter) rising from an initial salt layer located at < 7 km depth. We constrain the salt diapir viscosity by comparing the InSAR surface deformation pattern with results from numerical simulations and our best fitting model is obtained for a salt viscosity of 1 × 1017 Pa s. The best fitting model reveals the presence of a relatively small salt diapir that has not pierced yet the entire sedimentary layer and is located just 1–2 km below the surface.

Download Full-text

The generation of gravity–capillary solitary waves by a pressure source moving at a trans-critical speed

Journal of Fluid Mechanics ◽

10.1017/jfm.2016.658 ◽

2016 ◽

Vol 810 ◽

pp. 448-474 ◽

Cited By ~ 7

Author(s):

Naeem Masnadi ◽

James H. Duncan

Keyword(s):

Free Surface ◽

Numerical Simulations ◽

Model Equation ◽

Surface Deformation ◽

Phase Speed ◽

Capillary Waves ◽

Deformation Pattern ◽

Pressure Source ◽

Exponential Decay Law ◽

Response State

The unsteady response of a water free surface to a localized pressure source moving at constant speed $U$ in the range $0.95c_{min}\lesssim U\leqslant 1.02c_{min}$, where $c_{min}$ is the minimum phase speed of linear gravity–capillary waves in deep water, is investigated through experiments and numerical simulations. This unsteady response state, which consists of a V-shaped pattern behind the source, and features periodic shedding of pairs of depressions from the tips of the V, was first observed qualitatively by Diorio et al. (Phys. Rev. Lett., vol. 103, 2009, 214502) and called state III. In the present investigation, cinematic shadowgraph and refraction-based techniques are utilized to measure the temporal evolution of the free-surface deformation pattern downstream of the source as it moves along a towing tank, while numerical simulations of the model equation described by Cho et al. (J. Fluid Mech., vol. 672, 2011, pp. 288–306) are used to extend the experimental results over longer times than are possible in the experiments. From the experiments, it is found that the speed–amplitude characteristics and the shape of the depressions are nearly the same as those of the freely propagating gravity–capillary lumps of inviscid potential theory. The decay rate of the depressions is measured from their height–time characteristics, which are well fitted by an exponential decay law with an order one decay constant. It is found that the shedding period of the depression pairs decreases with increasing source strength and speed. As the source speed approaches $c_{min}$, this period tends to approximately 1 s for all source magnitudes. At the low-speed boundary of state III, a new response with unsteady asymmetric shedding of depressions is found. This response is also predicted by the model equation.

Download Full-text

165 Effects of Digestible Lysine Level on Growth Performance and Economics of Grow-finish Pigs

Journal of Animal Science ◽

10.1093/jas/skab054.098 ◽

2021 ◽

Vol 99 (Supplement_1) ◽

pp. 58-59

Author(s):

Larissa L Becker ◽

Emily E Scholtz ◽

Joel M DeRouchey ◽

Mike D Tokach ◽

Jason C Woodworth ◽

...

Keyword(s):

Phase 1 ◽

Information Criterion ◽

Response Curves ◽

Phase 3 ◽

Ileal Digestibility ◽

Distillers Dried Grains ◽

Feed Cost ◽

Best Fitting ◽

Dietary Treatments ◽

Fitting Model

Abstract A total of 2,124 barrows and gilts (PIC 1050′DNA 600, initially 48.9 kg) were used in a 32-d study to determine the optimal dietary standardized ileal digestibility (SID) Lys level in a commercial setting. Pigs were randomly allotted to 1 of 5 dietary treatments with 24 to 27 pigs/pen and 16 replications/treatment. Similar number of barrows and gilts were placed in each pen. Diets were fed over 3 phases (48.9 to 58.6, 58.6 to 70.9, and 70.9 to 80.8 kg respectively). Dietary treatments were corn-soybean meal-based and contained 10 (phase 1 and 2) or 5% (phase 3) distillers dried grains with solubles. Diets were formulated to 85, 95, 103, 110, or 120% of the current Pig Improvement Company (PIC, Hendersonville, TN) SID Lys gilt recommendations with phase 1 SID Lys levels of 0.90, 1.01, 1.09, 1.17 and 1.27%, phase 2 levels of 0.79, 0.87, 0.94, 1.03, and 1.10%, and phase 3 levels of 0.71, 0.78, 0.85, 0.92, and 0.99%, respectively. Dose response curves were evaluated using linear (LM), quadratic polynomial (QP), broken-line linear (BLL), and broken-line quadratic (BLQ) models. For each response variable, the best-fitting model was selected using the Bayesian information criterion. Overall (d 0 to 32), increasing SID Lys increased (linear, P< 0.001) BW, ADG, G:F, Lys intake/d, and Lys intake/kg of gain. Modeling margin over feed cost (MOFC), BLL and QP estimated the requirement at 105.8% and 113.7% respectively. In summary, while growth increased linearly up to 120% of the PIC current feeding level, the optimal MOFC was 106% to 114% depending on the model used.

Download Full-text

Genetic and Environmental Influences of Dietary Indices in a UK Female Twin Cohort

Twin Research and Human Genetics ◽

10.1017/thg.2020.84 ◽

2020 ◽

Vol 23 (6) ◽

pp. 330-337

Author(s):

Olatz Mompeo ◽

Rachel Gibson ◽

Paraskevi Christofidou ◽

Tim D. Spector ◽

Cristina Menni ◽

...

Keyword(s):

Healthy Eating ◽

Menopausal Status ◽

Healthy Eating Index ◽

Healthy Diet ◽

Nutritional Epidemiology ◽

Best Fitting ◽

Heritability Estimates ◽

Fitting Model ◽

Dietary Indices ◽

Health Parameters

AbstractA healthy diet is associated with the improvement or maintenance of health parameters, and several indices have been proposed to assess diet quality comprehensively. Twin studies have found that some specific foods, nutrients and food patterns have a heritable component; however, the heritability of overall dietary intake has not yet been estimated. Here, we compute heritability estimates of the nine most common dietary indices utilized in nutritional epidemiology. We analyzed 2590 female twins from TwinsUK (653 monozygotic [MZ] and 642 dizygotic [DZ] pairs) who completed a 131-item food frequency questionnaire (FFQ). Heritability estimates were computed using structural equation models (SEM) adjusting for body mass index (BMI), smoking status, Index of Multiple Deprivation (IMD), physical activity, menopausal status, energy and alcohol intake. The AE model was the best-fitting model for most of the analyzed dietary scores (seven out of nine), with heritability estimates ranging from 10.1% (95% CI [.02, .18]) for the Dietary Reference Values (DRV) to 42.7% (95% CI [.36, .49]) for the Alternative Healthy Eating Index (A-HEI). The ACE model was the best-fitting model for the Healthy Diet Indicator (HDI) and Healthy Eating Index 2010 (HEI-2010) with heritability estimates of 5.4% (95% CI [−.17, .28]) and 25.4% (95% CI [.05, .46]), respectively. Here, we find that all analyzed dietary indices have a heritable component, suggesting that there is a genetic predisposition regulating what you eat. Future studies should explore genes underlying dietary indices to further understand the genetic disposition toward diet-related health parameters.

Download Full-text

GPS measurements on pre-, co- and post-seismic surface deformation at first multi-parametric geophysical observatory, Ghuttu in Garhwal Himalaya, India

Journal of Geodetic Science ◽

10.1515/jogs-2020-0114 ◽

2020 ◽

Vol 10 (1) ◽

pp. 136-144

Author(s):

P.K. Gautam ◽

S. Rajesh ◽

N. Kumar ◽

C.P. Dabral

Keyword(s):

Time Series ◽

Surface Deformation ◽

Translational Motion ◽

Anomalous Behavior ◽

Deformation Pattern ◽

Local Earthquakes ◽

Position Time Series ◽

Continuous Gps ◽

Gps Time Series ◽

Gps Station

Abstract We investigate the surface deformation pattern of GPS station at MPGO Ghuttu (GHUT) to find out the cause of anomalous behavior in the continuous GPS time series. Seven years (2007-2013) of GPS data has been analyzed using GAMIT/GLOBK software and generated the daily position time series. The horizontal translational motion at GHUT is 43.7 ± 1 mm/yr at an angle of 41°± 3° towards NE, while for the IGS station at LHAZ, the motion is 49.4 ±1 mm/yr at 18 ± 2.5° towards NEE. The estimated velocity at GHUT station with respect to IISC is 12 ± 1 mm/yr towards SW. Besides, we have also examined anomalous changes in the time series of GHUT before, after and during the occurrences of local earthquakes by considering the empirical strain radius; such that, a possible relationship between the strain radius and the occurrences of earthquakes have been explored. We considered seven local earthquakes on the basis of Dobrovolsky strain radius condition having magnitude from 4.5 to 5.7, which occurred from 2007 to 2011. Results show irrespective of the station strain radius, pre-seismic surface deformational anomalies are observed roughly 70 to 80 days before the occurrence of a Moderate or higher magnitude events. This has been observed for the cases of those events originated from the Uttarakashi and the Chamoli seismic zones in the Garhwal and Kumaun Himalaya. Occurrences of short (< 100 days) and long (two years) inter-seismic events in the Garhwal region plausibly regulating and diffusing the regional strain accumulation.

Download Full-text

Comparing productive vocabulary measures from the CDI and a systematic diary study

Journal of Child Language ◽

10.1017/s0305000998003663 ◽

1999 ◽

Vol 26 (1) ◽

pp. 177-185 ◽

Cited By ~ 22

Author(s):

BYRON F. ROBINSON ◽

CAROLYN B. MERVIS

Keyword(s):

Growth Curves ◽

Diary Study ◽

Expressive Vocabulary ◽

Early Language ◽

Vocabulary Size ◽

Early Language Development ◽

Closed Class ◽

Communicative Development ◽

Best Fitting ◽

Fitting Model

Expressive vocabulary data gathered during a systematic diary study of one male child's early language development are compared to data that would have resulted from longitudinal administration of the MacArthur Communicative Development Inventories spoken vocabulary checklist (CDI). Comparisons are made for (1) the number of words at monthly intervals (9;10.15 to 2;0.15), (2) proportion of words by lexical class (i.e. noun, predicate, closed class, ‘other’), (3) growth curves. The CDI underestimates the number of words in the diary study, with the underestimation increasing as vocabulary size increases. The proportion of diary study words appearing on the CDI differed as a function of lexical class. Finally, despite the differences in vocabulary size, logistic curves proved to be the best fitting model to characterize vocabulary development as measured by both the diary study and the CDI. Implications for the longitudinal use of the CDI are discussed.

Download Full-text

Identification-Robust Estimates of the Canadian Natural Rate of Interest

L Actualité économique ◽

10.7202/1036918ar ◽

2016 ◽

Vol 91 (1-2) ◽

pp. 161-176

Author(s):

Maral Kichian

Keyword(s):

Interest Rate ◽

Robust Methods ◽

Errors In Variables ◽

Natural Rate ◽

Real Rate ◽

Point Estimates ◽

Natural Rate Of Interest ◽

Best Fitting ◽

Estimate Precision ◽

Fitting Model

The natural rate of interest is an unobservable entity and its measurement presents some important empirical challenges. In this paper, we use identification-robust methods and central bank real-time staff projections to obtain estimates for the equilibrium real rate from contemporaneous and forward-looking Taylor-type interest rate rules. The methods notably account for the potential presence of endogeneity, under-identification, and errors-in-variables concerns. Our applications are conducted on Canadian data. The results reveal some important identification difficulties associated with some of our models, reinforcing the need to use identification-robust methods to estimate such policy functions. Despite these challenges, we are able to obtain fairly comparable point estimates for the real equilibrium interest rate across our different models, and in the case of the best fitting model, also remarkable estimate precision.

Download Full-text

Forward Modelling of Bouguer Anomalies along a transect of the Southern Apennines and the Tyrrhenian back-arc basin.

10.5194/egusphere-egu21-12246 ◽

2021 ◽

Author(s):

Assel Akimbekova ◽

Paolo Mancinelli ◽

Massimiliano Rinaldo Barchi ◽

Cristina Pauselli ◽

Giorgio Minelli

Keyword(s):

Gravity Anomalies ◽

Moho Depth ◽

Positive Trend ◽

Tyrrhenian Sea ◽

Southern Apennines ◽

Bouguer Anomalies ◽

Crustal Model ◽

Density Values ◽

Best Fitting ◽

Fitting Model

Abstract&#160;In the present study, starting from original measurement stations, we created the Bouguer anomaly map of Southern Italy with a reduction density of 2670 kg m-3. We perform a regional gravity modelling at crustal scale along the trace of the CROP-04 (on-shore) and MB6 (off-shore) deep seismic reflection profiles crossing the Southern Apennines and the Southern Tyrrhenian Sea. Along the 320 km-long modelled profile, we investigate crustal-scale sources for the observed gravity anomalies.&#160;After a compelling review of the published Moho geometries in the area, that were retrieved from either active or passive seismic methods, we test them in the observed gravity field through forward modeling of the Bouguer gravity anomalies. The comparison between the different Moho interpretations shows that the steepness of the subducting slab, the position of the step between the western (Tyrrhenian) and the eastern (Adriatic) Moho and Moho depth represent the main features influencing the observed Bouguer anomalies at crustal scale.Finally, we provide a best-fitting model across both onshore and offshore areas. In the proposed best-fitting model, the wide wavelength and strong regional Bouguer anomalies correlate with the geometry of the Moho discontinuity and deep tectonic structures. On the other hand, the small-amplitude oscillations of the gravity anomalies were attributed to the low-density values of the Pliocene-Quaternary deposits both on- (e.g. the Bradanic trough) and off-shore (e.g. recent deposits in the Tyrrhenian sea bottom). Gravity minima correspond to the crustal doubling underneath the Southern Apennines where the Tyrrhenian Moho (~27 km depth) overlies the deeper Adriatic Moho (~50 km depth). The positive trend of the observed anomaly toward NE is related to the shallowing of the Adriatic Moho to depths of ~28 km in the Adriatic. Similarly, towards SW, the observed anomaly follows a positive trend towards the maxima located in the Central Tyrrhenian Sea. We model this trend as representative of crustal thinning and shallowing to values of ~12 km depth of the Tyrrhenian Moho. We also model a crustal transition from geometries and density values typical of a continental crust in the Adriatic domain towards a more oceanic structure and composition in the Tyrrhenian domain. This crustal model locates the westward flexure of the Adriatic Moho, mimicking the subduction of the Adriatic lithosphere beneath the Peri-Tyrrhenian block and locates step between the western (Tyrrhenian) and the eastern (Adriatic) Moho beneath the Apennines range.The resulted gravity forward model provide contributions to the tectonic settings understanding of the area by providing a robust crustal model ranging from the Tyrrhenian Sea to the Apulian foreland.&#160;Finally, we believe that the proposed model can serve as a starting point for future studies investigating the upper crustal geometries in the area and addressing open questions about its relations with seismicity distribution.&#160;

Download Full-text

Optimal Self-Propulsion of a Deformable Prolate Spheroid

Journal of Ship Research ◽

10.5957/jsr.1983.27.2.121 ◽

1983 ◽

Vol 27 (02) ◽

pp. 121-130

Author(s):

T. Miloh

Keyword(s):

Kinetic Energy ◽

Surface Deformation ◽

Deformable Body ◽

Large Degree ◽

Prolate Spheroid ◽

The Body ◽

Deformation Pattern ◽

Inviscid Fluid ◽

Periodic Surface ◽

Deformation Velocity

The problem of self-propulsion of an elongated deformable body moving in an infinite medium of inviscid fluid is considered in some detail. A prolate spheroid is chosen as a model shape, and a particular deformation pattern which maximizes the Froude efficiency is sought. The Froude efficiency in this context is defined by the ratio of the kinetic energy of the body to the total kinetic energy of the system comprising the body and the fluid. It is demonstrated that a body can propel itself from rest in a persistent manner even for a periodic surface deformation with zero mean which preserves both the volume and the location of its centroid. Under these constraints the induced forward velocity of the body is of 0(ε2) where ε is the amplitude of the deformation velocity. It is also demonstrated that for a persistent self-propulsion to exist the body should develop a large degree of skewness, resulting from the interaction between the two deformation components—one with fore-and-aft symmetry and one without. It is also essential that the symmetric and asymmetric deformation components should be out of phase.

Download Full-text

Multi-Sensor SAR Geodetic Imaging and Modelling of Santorini Volcano Post-Unrest Response

Remote Sensing ◽

10.3390/rs11030259 ◽

2019 ◽

Vol 11 (3) ◽

pp. 259 ◽

Cited By ~ 5

Author(s):

Elena Papageorgiou ◽

Michael Foumelis ◽

Elisa Trasatti ◽

Guido Ventura ◽

Daniel Raucoules ◽

...

Keyword(s):

Deformation Pattern ◽

Volcano Deformation ◽

Isotropic Source ◽

Synthetic Aperture Radar Interferometry ◽

Spatial Deformation ◽

Deformation State ◽

Multi Temporal ◽

History Of ◽

Best Fitting ◽

Santorini Volcano

Volcanic history of Santorini over recent years records a seismo-volcanic unrest in 2011–12 with a non-eruptive behavior. The volcano deformation state following the unrest was investigated through multi-sensor Synthetic Aperture Radar Interferometry (InSAR) time series. We focused on the analysis of Copernicus Sentinel-1, Radarsat-2 and TerraSAR-X Multi-temporal SAR Interferometric (MT-InSAR) results, for the post-unrest period 2012–17. Data from multiple Sentinel-1 tracks and acquisition geometries were used to constrain the E-W and vertical components of the deformation field along with their evolution in time. The interpretation of the InSAR observations and modelling provided insights on the post-unrest deformation pattern of the volcano, allowing the further re-evaluation of the unrest event. The increase of subsidence rates on Nea Kameni, in accordance with the observed change of the spatial deformation pattern, compared to the pre-unrest period, suggests the superimposition of various deformation sources. Best-fitting inversion results indicate two deflation sources located at southwestern Nea Kameni at 1 km depth, and in the northern intra-caldera area at 2 km depth. A northern sill-like source interprets the post-unrest deflation attributed to the passive degassing of the magma intruded at 4 km during the unrest, while an isotropic source at Nea Kameni simulates a prevailing subsidence occurring since the pre-unrest period (1992–2010).

Download Full-text

A physics-based approach of deep interseismic creep for viscoelastic strike-slip earthquake cycle models

Geophysical Journal International ◽

10.1093/gji/ggz426 ◽

2019 ◽

Vol 220 (1) ◽

pp. 79-95

Author(s):

Lucile Bruhat

Keyword(s):

Surface Deformation ◽

Slip Rate ◽

Strike Slip ◽

Dynamic Rupture ◽

Crust And Upper Mantle ◽

Slip Rates ◽

Region I ◽

Best Fitting ◽

Time Invariant ◽

Analytical Expressions

SUMMARY Most geodetic inversions of surface deformation rates consider the depth distribution of interseismic fault slip-rate to be time invariant. However, some numerical simulations show downdip penetration of dynamic rupture into regions with velocity-strengthening friction, with subsequent updip propagation of the locked-to-creeping transition. Recently, Bruhat and Segall developed a new method to characterize interseismic slip rates, that allows slip to penetrate up dip into the locked region. This simple model considered deep interseismic slip as a crack loaded at its downdip end, and provided analytical expressions for stress drop within the crack, slip and slip rate along the fault. This study extends this approach to strike-slip fault environments, and includes coupling of creep to viscoelastic flow in the lower crust and upper mantle. I use this model to investigate interseismic deformation rates along the Carrizo Plain section of the San Andreas fault. This study reviews possible models, elastic and viscoelastic, for fitting horizontal surface rates. Using this updated approach, I develop a physics-based solution for deep interseismic creep which accounts for possible slow vertical propagation, and investigate how it improves the fit of the horizontal deformation rates in the Carrizo Plain region. I found solutions for fitting the surface deformation rates that allow for reasonable estimates for earthquake rupture depth and coseismic displacement and improves the overall fit to the data. Best-fitting solutions present half-space relaxation time around 70 yr, and very low propagation speeds, less than a metre per year, suggesting a lack of creep propagation.

Download Full-text