Decay Period Research Articles

Effect of Water Hyacinth (Eichhornia crassipes) Mulch on Soil Microbial Properties in Lowland Rainfed Rice-Based Agricultural System in Northeast India

Most water bodies in the humid tropical areas of Arunachal Pradesh are infested with gregarious Eichhornia crassipes (Mart.) Solms. Over a period of time, with death and decay, the water bodies are eutrophicated. This natural phenomenon gave forth the idea of using E. crassipes biomass as a compost in agricultural fields for soil nutrients management, using microbial characteristics as potential indicators. The study indicating that water hyacinth as a potential organic substrate can stimulate the growth of diversity of microbial population in agricultural soils. In general, soil respiration and microbial population were significantly (p < 0.05) greater in mulched plots compared to control. Among treatments, vermicompost mulched plots recorded for higher bacterial (74.31 CFU × 104) and fungal counts (31.09 CFU × 103) at both surface and sub-surface soil layers. The present study provides baseline information for ecofriendly approach to management of E. crassipes, especially for the countries where it poses a huge threat to the wetland ecosystems. Nonetheless, nutrient deficient soils in the present study site due mainly to conventional farming practices and nutrient runoff could however be checked by mulching soils with naturally and abundantly growing E. crassipes locally.

Further insights into self-similarity and self-preservation in freely decaying isotropic turbulence

An investigation of some open issues in homogeneous isotropic turbulence (HIT) decay is proposed in the present paper. More specifically, several apparent paradoxical or controversial issues, among which the existence of solutions satisfying complete self-similarity and complete self-preservation, are investigated via theoretical analysis and numerical results. The investigated range of Reynolds numbers encompasses values from Reλ = 10−4 to Reλ = 105, which are far beyond capabilities of existing wind tunnels and DNS. Thus, this analysis offers an almost unique opportunity to cover at the same time all possible decay regimes, from the high-Reynolds initial decay period to the low-Reynolds final decay period. The numerical analysis of such an extended range of Reλ is achieved by the use of the Eddy-Damped Quasi-Normal Markovian (EDQNM) model. Moreover, the high versatility of this model enabled a complete screening of HIT decay in terms of the initial conditions, and in particular the influence of the slope of the energy spectrum at large scales so that σ ∈ [1,4], E(k → 0) ∼ kσ has been extensively investigated. The analysis of the Lin equation shows that a complete self-similar decay regime occurs for σ = 1 only, and that all existing theories, including George’s theory, collapse in this case. Moreover, numerical results indicate that HIT does not lose memory of its initial conditions, i.e. no universal asymptotic behaviour derived by fixed-point analysis is recovered after very long time decay. As a confirmation, it is shown that a decay regime such that occurs for σ = 1 only, and from the initial time. Consequently, results of the fixed-point analysis of equations must not be considered as the evidence of a possible universal asymptotic behaviour, as they are valid in the sole case σ = 1.

Dynamical Influences of Anvil Shading on Simulated Supercell Thunderstorms

Abstract Numerical simulations of supercell thunderstorms including parameterized radiative transfer and surface fluxes are performed using the Advanced Regional Prediction System (ARPS) model to investigate how low-level air temperature deficits within anvil shadows affect the simulated storms. The maximum temperature deficits within the modeled cloud shadows are 1.5–2.0 K, which is only about half that previously observed. Within the shadows, the loss of strong solar heating cools and stabilizes the near-surface layer, which suppresses vertical mixing and modifies the near-surface vertical wind shear. In a case of a stationary storm, the enhanced easterly shear present beneath the anvil leads to a thinning of the outflow layer and corresponding acceleration of the rear-flank gust front far ahead of the overlying updraft, weakening the low-level mesocyclone. It is further shown that the direct absorption and emission of radiation by clouds does not significantly affect the simulated supercells. Varying the time of day of model initialization does not prevent the simulated storms from weakening. This behavior is mirrored for storms that slowly move along the major axis of the anvil shadow. If the rear-flank gust front moves into the anvil shadow and the updraft moves normal to the shadow (i.e., northward movement of the updraft), cyclic periods of intensification and decay can result, although this result is likely highly dependent on the storm-relative wind profile. If the gust front does not advance into the shaded region (i.e., southward movement), or if the storm moves rapidly, the storm is relatively unaffected by anvil shading because the rear-flank gust front speed and outflow depth remain relatively unchanged.

Homogeneous Turbulence in a First-order Reactant for the Case of Multi-point and Multi-time Prior to the Final Period of Decay in a Rotating System

Using Deissler’s approach, the decay for the concentration of a dilute contaminant undergoing a first- order chemical reaction in homogeneous turbulence at times prior to the final period of decay in a rotating system for the case of multi-point and multi-time is studied. Here two and three point correlations between fluctuating quantities have been considered and the quadruple correlations are ignored in comparison to the second and third order correlations. Taking Fourier transform the correlation equations are converted to spectral form. Finally, integrating the energy spectrum over all wave numbers we obtained the decay law for the concentration fluctuations in a homogeneous turbulence prior to the final period in a rotating system for the case of multi-point and multi-time.

Diurnal variations in the intensity of tropical cyclones

We statistically study diurnal variations in the maximum wind velocity in tropical cyclones on the basis of vast experimental material. We have found notable oscillations in the acceleration of rotation velocity (rate of variations in the maximum wind velocity), which are most pronounced in the periods of intensification and decay of the cyclones. The diurnal variations can differ notably in phase in different geographical conditions.

Effect of MnO4− and silver content on electrochemical behaviour of Pb–Ag alloy anodes during potential decay periods

The effect of MnO4− and silver content on electrochemical behaviour of five commercial Pb–Ag alloy anodes was studied in acid zinc sulphate electrolyte with and without MnO4− ions at 38 °C during potential decay periods. When the anodes were immersed into acid zinc sulphate electrolyte without MnO4− ions, the Pb–0.72%Ag anode entered complete passivation state in the shortest time among the five anodes, followed by anodes Pb–0.67%Ag, Pb–0.60%Ag, Pb–0.58%Ag and Pb–0.29%Ag– 0.1%Ca by measurement of open circuit potential. During immersion of the anodes, MnO4− ions accelerated the passivation and increased the corrosion current density of the anodes. After immersion in zinc electrolyte with MnO4−, the anode Pb–0.72%Ag had the best corrosion resistance, followed by anodes Pb–0.67%Ag, Pb–0.60%Ag, then the close anodes Pb–0.58%Ag and Pb–0.29%Ag– 0.1%Ca by the electrochemical impedance spectroscopy (EIS) analysis.

Abnormal cytoplasmic calcium dynamics in central neurons of a dystonia mouse model

Increased activities of cytoplasmic calcium and the excitatory neurotransmitter glutamate have been independently implicated in dystonia pathophysiology. However, cellular-level evidence linking these two features is not available. Here we show that glutamate-dependent changes in neuronal calcium dynamics occur in a knock-in mouse model of DYT1 dystonia, the most common hereditary form of this disorder. Fluorescence-based analysis of the dynamics of cytoplasmic calcium concentration ([Ca2+]c) in cultured hippocampal neurons shows that electrical stimulation depolarizes the neurons and increases the dendritic [Ca2+]c, which then decays slowly to the pre-stimulus level. Whereas the peak amplitude of [Ca2+]c was not affected, the decay period was prolonged in neurons of heterozygous mice whose genotype reflects the human condition. We found that this effect was blocked by the antagonists of ionotropic glutamate receptors, and confirmed that glutamate receptors are present in these neurons. As the [Ca2+]c is readout and regulator of neuronal excitability, its abnormality represents an important cellular phenotype of dystonia

Long‐term loss and re‐formation of the outer radiation belt

AbstractThe Earth's outer radiation belt is known to vary often and significantly on various time scales. In this study, we have used the data of various instruments onboard the THEMIS spacecraft to study long‐term changes of the outer radiation belt electrons around the year 2009. We find that the entire outer belt became extremely weak for nearly a year and was practically lost a few times, each time lasting ~20 days up to ~2 months, before eventually re‐forming. This was revealed at a wide energy range from several tens of keV to up to 719 keV, which was covered by the THEMIS spacecraft measurements. The loss of the outer belt was associated with extremely weak solar wind conditions, i.e., low interplanetary magnetic field magnitude and slow solar wind speed. In particular, this set greatly reduced magnetospheric convection and/or injections for a prolonged time interval, which led to a large expansion of the plasmasphere, even beyond geosynchronous altitude and thus invading the majority of the typical outer belt territory for the same prolonged time interval. Consequently, preexisting electrons inside the plasmasphere had enough time to be lost into the atmosphere gradually over a time scale of several days without being supplied with fresh electrons from the plasma sheet under the same reduced convection and/or injections. Plasmaspheric hiss waves with an amplitude of up to a few tens of pT persisted to exist during the gradual decay periods, implying that they are likely responsible for the continual loss of the electrons inside the plasmasphere. A complete re‐formation of the outer belt to full intensity was then realized over an interval of a few months. During the re‐formation process, the magnetospheric convection and/or injections increased, which led to a gradual increase of whistler chorus wave activity, contraction of the plasmasphere, and supply of the plasma sheet electrons at high L shells. This set first an outward increasing profile of the phase space density, which eventually developed into a profile with a peak at low L of ~5 over a time scale of 1–2 days. In this latter stage, a local acceleration at low L shells is found to be clearly needed although the radial diffusion process can contribute to some extent, in particular, for particles with a low first adiabatic invariant value.

Performance of Pb–Ag anodes during polarisation and decay periods in zinc electrowinning

The performance of different Pb–Ag (0·5, 0·6 and 0·7%) anodes during zinc electrowinning has been investigated in acid zinc sulphate electrolyte containing Mn2+ at 38°C, and 50 mA cm−2. After 24 h of electrolysis, the polished surface of the polarised anode Pb–0·7Ag (wt-%) had the lowest overpotential [685 mV(SHE)], followed by that of Pb–0·6Ag (707 mV) and finally by Pb–0·5Ag (732 mV). During the decay period, the corrosion potential of the Pb–0·7Ag anode reached the steady stationary state (298 mV) after ∼29 h, while the potentials of Pb–0·6Ag (350 mV) and Pb–0·5Ag (600 mV) anodes were still unstable after 240 h decay. It was found from electrochemical noise measurements that during ∼204 h decay, the Pb–0·5Ag anode had the highest admittance rate ‘1/Rn’ (proportional to corrosion rate) among the three anodes, followed by the anodes Pb–0·60Ag and Pb–0·70Ag. The fluctuations of potential time record of 0·5Ag lead anode were more frequent, smooth and with equal amplitudes than that of 0·7% Ag lead, possibly due to the difference in the passive behaviour, quantity and adhesion of corrosion products. The absolute magnitudes of the power spectral densities ‘PSD’ slopes of current and potential of Pb–0·5Ag anode were lower than that of 0·7%Ag lead anode, indicating that the corrosion form was more uniform for Pb–0·5Ag anode.La performance des différentes anodes de Pb–Ag (0·5, 0·6 et 0·7%) durant zinc electrowinning a été investiguée dans un électrolyte acide de sulfate de zinc contenant Mn2+ à 38°C et 50 mA cm−2. Après 24 h d’électrolyse, la surface polie de l’anode polarisée Pb–0·7Ag avait la plus basse surtension [685 mV(SHE)], suivie par celle de Pb–0·6%Ag (707 mV) et finalement par Pb–0·5Ag [(732 mV(SHE)]. Pendant la période d'affaiblissement, le potentiel de corrosion de l'anode de Pb–0·7Ag est arrivé à l’état stationnaire stable (298 mV) après ∼29 h, alors que les potentiels des anodes de Pb–0·6Ag (350 mV) et de Pb–0·5Ag (600 mV) étaient encore instables après affaiblissement de 240 h. Durant l’affaiblissement (∼204 h), l’anode de Pb–0·5Ag avait la plus grande admittance ≪ 1/Rn ≫ (proportionnelle à la vitesse de corrosion) parmi les trois anodes, suivie par les anodes Pb–0·60Ag et Pb–0·70Ag. Les fluctuations enregistrées du potentiel-temps d'anode de plomb 0·5Ag étaient plus fréquents, lisse et avec des amplitudes égales que celles de Pb–0·7Ag, probablement en raison de la différence dans le comportement passif, de la quantité et l’adhérence des produits de corrosion. Les magnitudes absolues des pentes de densité spectrale de puissance ≪PSD≫ de courant et potentiel de l’anode Pb–0·5Ag étaient inférieures à celles de Pb–0·7Ag, indiquant que la forme de corrosion était plus uniforme pour Pb–0·5Ag.

Planar Laser-Induced Fluorescence Diagnostics for Spatiotemporal OH Evolution in Pulsed Corona Discharge

OH radicals play an important role in pollutant removal in nonthermal plasmas. It is crucial to clarify the behavior of OH radicals in this process. A time-resolved 2-D OH radial distribution was investigated in a pulsed corona discharge by planar laser-induced fluorescence at atmospheric pressure and room temperature. The OH evolutions under different gas components were studied, and the evolution process was simulated. The OH decay processes were found to be divided into two periods: a fast decay period and a slow decay period. The O, N, and HO2 are dominant radicals for OH generation and decay. The OH radicals are mainly generated near a nozzle electrode. The concentration variations of O2, NO, and H2O in the background gas led to different OH density evolutions. The OH distribution zones were different as gas components varied. The maximum area of OH radical distribution after discharge decreased by 20% as O2 increased from 5% to 8 %, and it decreased by 69% as NO (150 ppm) was added into the background gas.

Insights into extracellular polymeric substances of cyanobacterium Microcystis aeruginosa using fractionation procedure and parallel factor analysis

Investigations on the extracellular polymeric substances (EPS) are crucial for better understanding the growth and proliferation of cyanobacterium Microcystis aeruginosa. In this study, a combined approach of fractionation procedure and parallel factor (PARAFAC) analysis were applied to characterize the EPS of M. aeruginosa. Physicochemical analysis showed that the contents of polysaccharides in EPS matrix were higher than those of proteins, regardless of the differences in growth phases and nutritional levels in medium. Organic matters were mainly distributed in the tightly bound EPS (TB-EPS) fraction during the exponential growth phase, whereas they sharply released to the soluble EPS (SL-EPS) and loosely bound EPS (LB-EPS) fractions at the decay period. Fluorescence excitation–emission matrix (EEM) was applied to characterize the specific compositions in EPS matrix, and all the fluorescence EEM spectra collected could be successfully decomposed into a four-component model by PARAFAC analysis. Component 1 [excitation/emission (Ex/Em) = 220/340], component 2 (Ex/Em = 280/340) and component 3 [Ex/Em = (200, 220, 270)/296] were attributed to protein-like substances, while component 4 [Ex/Em = (250, 340)/438] belonged to humic-like substances. Pearson correlation analysis demonstrated that tryptophan-like substances in the LB-EPS and TB-EPS fractions were positively correlated with Microcystis growth, whereas in the SL-EPS fraction, tryptophan-like as well as humic-like substances were associated with the growth of M. aeruginosa. The scientific implication for Microcystis growth and proliferation, based on the results of fractionation procedure and EEM-PARAFAC analysis, was also presented.

Numerical simulation of grid-generated turbulent particulate flow by three-dimensional Reynolds stress

A three-dimensional (3D) Reynolds stress turbulence model based on 3D Reynolds-averaged Navier-Stokes equations has been elaborated for grid-generated turbulence in particulate downward flow arranged in the channel domain of the square cross section. The model presented considers both the enhancement and attenuation of turbulence by means of the additional terms of the transport equations of the normal Reynolds stress components. It allows us to carry out calculations covering the long distance of the channel length without using algebraic assumptions for various components of the Reynolds stress. The results obtained show the effects of particles and mesh size of the turbulence generating grids on turbulence modification. In particular, the presence of solid particles at the initial period of turbulence decay results in the pronounced enhancement of turbulence that diminishes appreciably downwards in the area of typical channel turbulent flow. As the results show, the character of modification of all three normal components of the Reynolds stress taking place at the initial period of turbulence decay are uniform almost all over the channel cross sections. The increase in the grid mesh size slows down the rate of the turbulence enhancement which is caused by particles.

Influence of silver content and MnSO4 addition on performance of different lead–silver alloys during polarisation and decay periods

The electrochemical activity and the corrosion properties of five commercial lead anodes were examined by the conventional polarisation methods and the electrochemical impedance spectroscopy method. The results show that the anode Pb–0·62Ag alloy had a lower overpotential for anode reaction than the others. The corrosion resistance after polarisation of the anode Pb–0·62Ag alloy was higher than that of the Pb–0·29Ag–0·1Ca alloy, Pb–0·58Ag alloy and Pb–0·67Ag alloy, but lower than that of the anode Pb–0·72Ag alloy. However, the anode Pb–0·72Ag alloy had the highest overpotential. When anodes Pb–0·72Ag alloy and Pb–0·62Ag alloy were used, the cathode current efficiencies were higher, while anodes Pb–0·29Ag–0·1Ca alloy, Pb–0·58Ag alloy and Pb–0·67Ag alloy gave lower current efficiency. Regarding these several factors, the anode Pb–0·62Ag alloy is the best choice.On a examiné l’activité électrochimique et les propriétés de corrosion de cinq anodes commerciales en plomb, au moyen des méthodes conventionnelles de polarisation et de la méthode de spectroscopie d’impédance électrochimique. Les résultats montrent que l’anode de Pb–0·62Ag avait une surtension plus basse que celle des autres pour la réaction de l’anode. La résistance à la corrosion après la polarisation de l’anode de Pb–0·62Ag était plus élevée que pour l’anode de Pb–0·29Ag–0·1Ca, l’anode de Pb–0·58Ag ou l’anode de Pb–0·67Ag, mais plus basse que celle de l’anode de Pb–0·72Ag. Cependant, l’anode de Pb–0·72Ag avait la surtension la plus élevée. Lorsqu’on utilisait les anodes de Pb–0·72Ag ou de Pb–0·62Ag, le rendement du courant de la cathode était plus élevé, alors que les anodes de Pb–0·29Ag–0·1Ca, de Pb–0·58Ag et de Pb–0·67Ag donnaient un rendement de courant plus bas. Par rapport aux divers facteurs, l’anode de Pb–0·62Ag constitue le meilleur choix.

Identification of spontaneous fission fragments by using thermally annealed PADC films

One of main requirements in applied nuclear physics is the need of a detector capable of detecting and differentiating different particles. Thus, the fission products from a ^{252}Cf radioactive source, after about 12 half-life periods of alpha decay, are registered using virgin and annealed CR-39 polyallyldiglycol carbonate (PADC) films. In the case of virgin CR-39, a single peak appears corresponding to the heavy group of these products, while the other peak related to the light group is obscured. The annealed CR-39 detectors, on the other hand, were demonstrated to be highly sensitive to the fission fragments, and as a result we have observed the characteristic twin peaks of fission fragments from that radioactive source.

Decay and half-life period of online citations cited in open access journals

This study investigates the decay and half-life of online citations cited in four open access journals published between 2000 and 2009. A total of 1158 online citations cited in 1086 research articles published in two science and social science journals spanning a period of 10 years (2000–2009) were extracted. Study found that 24.58% (267 out of 1086) of articles had online citations and these articles contained a substantially very less number of online citations (2.98%) compared to previous study results. 30.56% (26% in Science and 52.73% in Social Science) of online citations were not accessible and remaining 69.44% of online citations were still accessible. The ‘HTTP 404 error message-page not found’ was the overwhelming message encountered and represented 67.79% of all HTTP message. Domains associated with .ac and .net had higher successful access rates while .org and .com/.co had lowest successful access rates. The half-life of online citations was computed to be approximately 11.5 years and 9.07 years in Science and Social science journal articles respectively.

Milankovitch tuning of deep-sea records: Implications for maximum rates of change of sea level

The analysis of several stacked and tuned records from the deep-sea floor yields two rather different sets of values for rates of sea-level rise. One of these reflects “regular” growth and decay and the other represents rapid decay of polar ice. Typical rise rates during rapid decay are near 1.2 m per century; with higher values seemingly following an abundance distribution that may be described by a standard deviation of 0.4 m per century (one third of the typical value). Distributions are based on a millennium resolution, leaving room for higher values for selected centuries within any millennium. Nevertheless, rise values beyond 5 m per century seem highly unusual. The quality of the match between deep-sea record (taken as differential) and Milankovitch forcing is excellent for the last 400,000 years (that is, the time since the “mid-Brunhes Event,” a period that may be referred to as the “Emiliani Chron”) but is poor in certain time spans before that. Difficulties associated with precise dating and a changing level of instability of polar ice prevent identification of trigger events for deglaciation. What is observable is that during periods of rapid decay, once sea level started to rise, it kept doing so for millennia (presumably till suitable ice masses were used up). Thus, it seems that a rise of sea level is itself a positive feedback on rapid melting of ice. Negative feedback, if real (as assumed in certain hypotheses about the origin of the Younger Dryas) is an unexpected exception that presumably relies on a high threshold value of sea-level rise.

Decay and half-life period of online citations cited in open access journals

This study investigates the decay and half-life of online citations cited in four open access journals published between 2000 and 2009. A total of 1158 online citations cited in 1086 research articles published in two science and social science journals spanning a period of 10 years (2000–2009) were extracted. Study found that 24.58% (267 out of 1086) of articles had online citations and these articles contained a substantially very less number of online citations (2.98%) compared to previous study results. 30.56% (26% in Science and 52.73% in Social Science) of online citations were not accessible and remaining 69.44% of online citations were still accessible. The ‘HTTP 404 error message-page not found’ was the overwhelming message encountered and represented 67.79% of all HTTP message. Domains associated with .ac and .net had higher successful access rates while .org and .com/.co had lowest successful access rates. The half-life of online citations was computed to be approximately 11.5 years and 9.07 years in Science and Social science journal articles respectively.

TESTING MODELS OF MAGNETIC FIELD EVOLUTION OF NEUTRON STARS WITH THE STATISTICAL PROPERTIES OF THEIR SPIN EVOLUTIONS

We test models for the evolution of neutron star (NS) magnetic fields (B). Our model for the evolution of the NS spin is taken from an analysis of pulsar timing noise presented by Hobbs et al. (2010). We first test the standard model of a pulsar's magnetosphere in which B does not change with time and magnetic dipole radiation is assumed to dominate the pulsar's spin-down. We find this model fails to predict both the magnitudes and signs of the second derivatives of the spin frequencies ($\ddot{\nu}$). We then construct a phenomenological model of the evolution of $B$, which contains a long term decay (LTD) modulated by short term oscillations (STO); a pulsar's spin is thus modified by its B-evolution. We find that an exponential LTD is not favored by the observed statistical properties of $\ddot{\nu}$ for young pulsars and fails to explain the fact that $\ddot{\nu}$ is negative for roughly half of the old pulsars. A simple power-law LTD can explain all the observed statistical properties of $\ddot{\nu}$. Finally we discuss some physical implications of our results to models of the B-decay of NSs and suggest reliable determination of the true ages of many young NSs is needed, in order to constrain further the physical mechanisms of their B-decay. Our model can be further tested with the measured evolutions of $\dot{\nu}$ and $\ddot{\nu}$ for an individual pulsar; the decay index, oscillation amplitude and period can also be determined this way for the pulsar.

Trace element determination in a mussel reference material using short irradiation instrumental neutron activation analysis

The production of certified reference materials in Brazil, and the consequent availability to national end users, is an important task for the enhancement of Metrology in Chemistry status in the country, as these materials are used for method validation, equipment calibration and for establishing metrological traceability links. In this study, Instrumental Neutron Activation Analysis (INAA) was applied to the determination of bromine, chlorine, magnesium, manganese, potassium and vanadium in a mussel reference material produced at IPEN-CNEN/SP. For the determination of these elements via the comparative INAA method, the respective analytical radionuclides, 80Br, 38Cl, 27Mg, 56Mn, 42K and 52V, are short lived and then, short irradiations are used. Six subsamples from two bottles of the Perna perna mussel reference material were analyzed. Each subsample was simultaneously irradiated with elemental standards for 10 s at the IEA-R1 research nuclear reactor through a pneumatic transfer system. After suitable decay periods, gamma radioactivity measurements were carried out, using a hyperpure germanium detector. The accuracy of the method was checked by using the NIST SRM 1566b–“Oyster Tissue” certified reference material. The comparison of the results obtained in this study to the robust mean of the interlaboratorial collaborative trial used for the characterization of the mussel reference material was performed via z-score tests. The comparison showed that the short irradiation INAA method is suitable for the characterization of new reference materials.

KILIMANJARO ICE CLIFF MONITORING WITH CLOSE RANGE PHOTOGRAMMETRY

Abstract. The glaciers on the summit plateau of Kibo, the main peak of the Kilimanjaro massif (3°S, 37°E, 5895 m a.s.l.) in Tanzania, are characterized by steep ice cliffs at their margins. These form-persistent cliffs continuously retreat and, consequently, govern the decrease in plateau glacier area. In order to quantify the ice cliff recession and study their morphology, close-range terrestrial photogrammetry combined with automatic stereo matching techniques was used to derive high resolution digital surface models of a south-facing “sample cliff” at four different dates. Results confirm, firstly, the annually bimodal nature of the recession being 15 cm/month during a 4.5 month sunlit phase and 2 cm/month during the remaining 7.5 month shaded phase, and, secondly, the tendency towards an “ideal cliff orientation”, which is either south- or north-facing and about 70°-75° steep. Moreover, the hypothesis of a predefined decay period for the plateau ice is supported by this study and it is shown that terrestrial photogrammetry is not only cheap and lightweight but also very suitable for ice surveys at the decameter scale.