Temperaturne razmere v mraziščih Komne Svetlin, Domen; Sinjur, Iztok; Ogrin, Matej
Dela (Univerza v Ljubljani. Oddelek za geografijo),
12/2023
60
Journal Article
Recenzirano
Odprti dostop
Raznoliko površje gorskih pokrajin omogoča pestro topoklimo in velike gradiente meteoroloških in klimatoloških elementov, med katere uvrščamo tudi temperaturo zraka. Mrazišča gorskega sveta kažejo ...zaostrene temperaturne razmere s povečanimi amplitudami, zlasti zaradi izstopajočih najnižjih temperatur. Po letu 2004 je raziskovanje mrazišč v Sloveniji dobilo nov zagon, pretekle raziskave, ki so bile osredotočene zlasti na rastne pogoje, so dobile nadgradnjo na klimatološkem področju. Neprekinjene meritve v več mraziščih, ki so jih izvajali različni raziskovalci v okviru Slovenskega meteorološkega foruma, so privedle do obsežne količine podatkov in spoznanj o temperaturnih razmerah v mraziščih, ki jih podrobneje predstavljamo v tem prispevku. Poleg novih najnižjih izmerjenih temperatur v Sloveniji se je izkazalo, da so, glede na neposredno okolico, letne povprečne temperature sredogorskih mrazišč nižje do 3 °C, povprečne najnižje pa do 7 °C. Temperature pod −30 °C se v Sloveniji v zadnjih desetletjih pojavljajo izključno v mraziščih, v sredogorju to velja tudi za temperature pod −20 °C. Najvišje temperature v mraziščih pa so zelo podobne tistim izven njih, lahko so celo nekoliko višje.
Bohinj je alpska kotlina na jugovzhodnem delu Julijskih Alp. Stalno je poseljena od starejše železne dobe, kolonizirali pa so jo ljudje iz Posočja zaradi bogatih nahajališč železove rude. ...Nastale so prve vasi v dolini z gospodarskim zaledjem v visokogorju, kot kažejo najdbe z Dolge planje na Prvem Voglu in Bošinke nad Dednim poljem. Keramika in ostanki temeljev koč nakazujejo možnost, da se je v tem času v visokogorju, poleg rudarjenja, začelo alpsko kmetovanje s sto- penjsko pašo iz vasi na visoka naravna travnata območja – planine, ki se je ohranilo vse do danes.
Na območju Triglavskega narodnega parka zasledimo poseben tip travnikov – grbinaste travnike. Zaradi človekove dejavnosti imajo grbinasti travniki ne le naravovarstveno, ampak tudi kulturno vrednost. ...Zato je od leta 2004 v Programu razvoja podeželja (PRP) vzpostavljen sistemski ukrep za ohranjanje grbinastih travnikov. Kmetje so za njihovo vzdrževanje upravičeni do izravnalnih plačil, a je ta podpora nizka, med manj poznanimi in zelo slabo uveljavljenimi. Uradni prostorski sloj grbinastih travnikov je, kljub terenski preveritvi in nadgradnji v letu 2021, necelovit in deloma pomanjkljiv. Namen članka je prikaz nove metode oziroma razvoja kvantitativnega postopka identifikacije grbinastih travnikov na območju Triglavskega narodnega parka. Omejitev postopka je, da ni neposredno uporaben za zaznavanje grbinastih travnikov brez naknadnega terenskega ali digitalnega pregleda. Z njegovo uporabo smo predstavili možnost učinkovite nadgradnje obstoječega uradnega prostorskega sloja grbinastih travnikov.
The solubility of ZrO2 in rutile is strongly temperature‐dependent and has been identified as a potentially powerful thermometer when the rutile coexists with an appropriate buffer assemblage, e.g. ...zircon + quartz. In combination with experimental data at 10 kbar, previous consideration of data on natural rutile has not identified a pressure dependence for the thermometer. However, the expected volume change as a result of substitution of the larger Zr4+ cation for Ti4+ suggests that the Zr content of rutile should decrease with increasing pressure. To investigate the pressure dependence of the thermometer, piston cylinder (at 10, 20 & 30 kbar) and 1 atm furnace experiments were performed in the system ZrO2‐TiO2‐SiO2. The solubility of ZrO2 in rutile, in the presence of zircon and quartz was reversed at each pressure value. From these experiments, the thermodynamics of the end‐member reaction ZrSiO4 = SiO2 + ZrO2 (in rutile) have been determined. There is a secondary pressure effect accompanying the primary temperature dependence of the Zr content of rutile. New thermometer equations are, in the α‐quartz field:
in the β‐quartz field
and in the coesite field
in which φ is ppm Zr, P is in kbar and R is the gas constant, 0.0083144 kJ K−1. Thermometric results using these equations are shown for a range of geological settings.
In this paper, we describe the investigations and actions taken to reduce risk and prevent casualties from a catastrophic 210,000 m
3
rockslope failure, which occurred near the village of Preonzo in ...the Swiss Alps on May 15, 2012. We describe the geological predisposition and displacement history before and during the accelerated creep stage as well as the development and operation of an efficient early warning system. The failure of May 15, 2012, occurred from a large and retrogressive instability in gneisses and amphibolites with a total volume of about 350,000 m
3
, which formed an alpine meadow 1250 m above the valley floor. About 140,000 m
3
of unstable rock mass remained in place and might collapse partially or completely in the future. The instability showed clearly visible signs of movements along a tension crack since 1989 and accelerated creep with significant hydromechanical forcing since about 2006. Because the active rockslide at Preonzo threatened a large industrial facility and important transport routes located directly at the toe of the slope, an early warning system was installed in 2010. The thresholds for prealarm, general public alarm, and evacuation were derived from crack meter and total station monitoring data covering a period of about 10 years, supplemented with information from past failure events with similar predisposition. These thresholds were successfully applied to evacuate the industrial facility and to close important roads a few days before the catastrophic slope failure of May 15, 2012. The rock slope failure occurred in two events, exposing a compound rupture plane dipping 42° and generating deposits in the midslope portion with a travel angle of 39°. Three hours after the second rockslide, the fresh deposits became reactivated in a devastating debris avalanche that reached the foot of the slope but did not destroy any infrastructure. The final run-out distance of this combined rock collapse–debris avalanche corresponded to the predictions made in the year 2004.
We investigated for magnetostratigraphy the Rio Nigra and Rio Frommer stratigraphic sections from Alpe di Siusi/Seiser Alm (Dolomites, northern Italy) in order to improve the calibration of the ...Triassic time scale. Both sections are characterized by ammonoid and conodont associations typical of Longobardian (late Ladinian, Middle Triassic) age. Moreover, the Rio Nigra section is constrained by a U-Pb zircon date of 237.77 ± 0.05 Ma. Building on the recently verified Newark-Hartford astrochronological polarity timescale for the Late Carnian–Rhaetian (plus the Hettangian) and through magnetostratigraphic correlations of an updated inventory of Tethyan marine stratigraphic sections from the literature, some of which are provided with U-Pb zircon age constraints, we propose a revised Geomagnetic Polarity Time Scale for the entire Triassic.
•New U-Pb constrained Ladinian magnetostratigraphy improves Triassic chronology.•Using recent magnetostratigraphic data to update the Geomagnetic Polarity Timescale•Updated Geomagnetic Polarity Timescale led to a duration of 50.5 Myr for Triassic.
Catastrophic landslides characterized by runaway slope failures remain difficult to predict. Here, we develop a physics‐based framework to prospectively assess slope failure potential. Our method ...builds upon the physics of extreme events in natural systems: the extremes so‐called “dragon‐kings” (e.g., slope tertiary creeps prior to failure) exhibit statistically different properties than other smaller‐sized events (e.g., slope secondary creeps). We develop statistical tools to detect the emergence of dragon‐kings during landslide evolution, with the secondary‐to‐tertiary creep transition quantitatively captured. We construct a phase diagram characterizing the detectability of dragon‐kings against “black‐swans” and informing on whether the slope evolves toward a catastrophic or slow landslide. We test our method on synthetic and real data sets, demonstrating how it might have been used to forecast three representative historical landslides. Our method can in principle considerably reduce the number of false alarms and identify with high confidence the presence of true hazards of catastrophic landslides.
Plain Language Summary
Catastrophic slope failures that pose great threats to life and property remain difficult to predict due to the strong variability of slope behavior. As a result, only a limited number of large rock slope failures have been so far successfully forecasted with associated risks mitigated. Here, we propose a novel predictive framework to prospectively and quantitatively detect slope failure precursors with high confidence. Our research sheds light on one of the most challenging questions in landslide prediction: Would an active landslide slowly move or catastrophically fail in the future? Our method adds a new conceptual framework and operational methodology with a significant potential to support existing early warning systems and hence reduce landslide risks.
Key Points
Tertiary creeps of catastrophic landslides accommodate dragon‐kings showing statistically different properties than secondary slope creeps
A predictive framework is developed to forecast catastrophic landslides by detecting signatures typical of the emergence of dragon‐kings
A phase diagram characterizes the detectability of dragon‐kings against black‐swans and discriminates catastrophic and slow landslides
In high-altitude environments, most of the debris-free glacier forelands are increasingly widening and the bare surfaces left by retreating glaciers offer the opportunity to investigate the evolution ...of soil through time. The main aim of this study is to discuss the applicability of a chronosequence approach in a deglaciated area, by considering the role of different soil forming factors. A study case has been selected (Alpe Veglia, Lepontine Alps), where field and laboratory characterizations were performed along a transect of 12 soil profiles from the proglacial area of the Aurona Glacier to the Alpe Veglia hollow, crossing different age glacial deposits. The results of soil physical and chemical analyses underline a time-trend of soil properties. On the other hand, even if the soil properties variability along the transect can be mainly explained according to the soil chronosequence approach, the data seem to highlight how the various soil forming factors (e.g. parent material, relief, vegetation) influence soil features, partly masking the effect of the time factor inducing a divergence from a traditional chronosequence. In particular, the morphology of the surrounding reliefs, depending on bedrock lithologies and structures, and the geomorphic dynamics seem to affect soil formation and evolution.
Renal hypouricemia (RHUC) is a disease caused by dysfunction of renal urate reabsorption transporters; however, diagnostic guidance and guidelines for RHUC have been lacking, partly due to the low ...evidence level of studies on RHUC. This review describes a world-first clinical practice guideline (CPG) and its first version in English for this condition. It was developed following the “MINDS Manual for Guideline Development” methodology, which prioritizes evidence-based medicine. It was published in Japanese in 2017 and later translated into English. The primary goal of this CPG is to clarify the criteria for diagnosing RHUC; another aim is to work towards a consensus on clinical decision-making. One of the CPG’s unique points is that it contains textbook descriptions at the expert consensus level, in addition to two clinical questions and recommendations derived from a systematic review of the literature. The guidance shown in this CPG makes it easy to diagnose RHUC from simple blood and urine tests. This CPG contains almost all of the clinical foci of RHUC: epidemiology, pathophysiology, diagnostic guidance, clinical examinations, differential diagnosis, and complications, including exercise-induced acute kidney injury and urolithiasis. A CPG summary as well as a clinical algorithm to assist healthcare providers with a quick reference and notes from an athlete for both physicians and patients are included. We hope that this CPG will help healthcare providers and patients to make clinical decisions, and that it will promote further research on RHUC.
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