Tržaški zaliv je plitvo robno morje, skrajni severni del Jadrana, ki je s treh strani omejen s kopnim. Ker je v njem razmeroma malo vode, manj kot v kakšnem velikem jezeru je izjemno občutljiv na ...ekološke spremembe. Geomorfološka dejstva nas opozarjajo na to, da so možnosti rabe zelo omejene. V prihodnje bo potrebno zelo skrbno, pretehtano in uravnoteženo ravnanje z naravnimi danostmi. Danes se zdi, da se ob umanjkanju dolgoročne razvojne vizije tega ne zavedamo dovolj.
--The paper presents the results of application of the CN algorithm to the area of the Southern External Dinarides. Two cases are considered--one for the knowledge gained throughout the considered ...period of time (1936-1996), and the other when learning ceased in 1986. In the first case 8 out of 9 strong earthquakes could have been predicted, three false alarms are declared (covering 7% of the total time considered) and TIPs occupy 32% of the total time. There is no clear relation between the TIPs duration and the size of the related earthquake. The second case (when the CN functions are defined on the basis of a shorter learning period) produces even slightly better results: only two false alarms are declared. In both cases current alarm exists in the region. All attempts to reduce the area of the regional polygon resulted in poorer prediction results.PUBLICATION ABSTRACT
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OBVAL, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
The horizontal components of 45 strong motion accelerograms recorded in Friuli, Italy, from May to September 1976, have been analyzed in order to estimate the stress drop of eight thrust faulting ...earthquakes. Two different stress parameters, the Brune stress drop Δσ and the apparent stress σa, have been considered. The Friuli main shock has a strong stress drop (Δσ ≈ 800 bars), while the aftershocks have stress drops which range from 250 to 400 bars. Five accelerograms written by the Montenegro, Yugoslavia, earthquake of April 1979 have also been analyzed. This thrust faulting earthquake had a stress drop of Δσ ≈ 900 bars. The stress drops of these thrust faulting earthquakes are compared to the stress drops determined by Rovelli et al. (1988a) for nine normal faulting earthquakes which occurred in the Apennines region from 1979 to 1984. The radiated energies and apparent stresses have also been calculated for the set of Apennine earthquakes. The thrust faulting earthquakes in the Alpine‐Dynaride region exhibit higher values for both the Brune and the apparent stress than the normal faulting earthquakes in the Apennines region. Excluding the Friuli and Montenegro main shocks, the Brune stress drops of the thrust faults are approximately 3 times those of the normal faults, while the apparent stresses are twice as large. This difference is statistically significant at a confidence level of 95%. The same difference also emerges from the scaling of the peak ground motions recorded in these two regions, suggesting an enhanced severity of the seismic input in the Alpine‐Dynaride environment compared with the Apennines.
The paper presents body-wave velocities in the crust and upper mantle of the circum-Adriatic region obtained by analyzing travel times of regional phases of 419 selected earthquakes with epicenters ...in the central part of the External Dinarides. The studied region was divided into five areas and two kinds of velocity models were determined for each of them. The first kind (
inter-area models) gives average velocities that characterize the zone between and including the epicentral region and the area in question, while the second kind (
intra-area models) presents velocities within the respective area.
The locations of hypocenters considerably improved when the new models were used instead of the standard one for the Balkan region. The large-scale variation of average velocities obtained by inter-area modeling was found to be relatively small both in the crust and in the upper mantle. On the other hand, the magnitude and distribution of station corrections and the resulting intra-area velocities point to relatively pronounced lateral velocity variation within some of the studied regions.
The obtained velocities in most cases do not differ significantly when compared to the values reported in other studies. The most important exceptions occur in the epicentral area (central part of the External Dinarides) where the P-wave velocity in the upper crust is much higher then elsewhere, while the velocity in the upper mantle is found to be lower than that determined by DSS experiments. There is also an indication of pronounced variation of the Poisson ratio in this area.
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IJS, IMTLJ, KILJ, KISLJ, NUK, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Tilt and strain gauge records are analysed to determine the long-term variations in space and time of the strain field in the Friuli area (NE Italy), located at the eastern boundary of the Adria ...plate. For such long-term variations a deep crustal origin is supposed. Spectral and cross-correlation analyses show that the strain energy involving a large area is polarized in two main directions, N20W and N70E, the first one characterized by aperiodic (or very long period, undetectable by the present analysis) variations, the second one by a period of about 8 years. The direction of the aperiodic motion (N20W) is normal to the Alpine chain, and parallel to the maximum horizontal compression acting in the Alpine area, whereas the direction of the 8 year period motion (N70E) is normal to the Dinaric Alps chain, and coincident with the maximum horizontal compression acting on the eastern boundary of the Adria plate, in the Balkans region. To explain such results, and particularly those related to the N70E direction, slow-travelling stress-strain waves are hypothesized.
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IJS, IMTLJ, KILJ, KISLJ, NUK, SBCE, SBJE, UL, UM, UPCLJ, UPUK
On the southwestern slope of Mt. Svilaja a Triassic sequence is exposed. It is composed of Lower Triassic carbonate siliciclastic shelf beds that are unconformably overlain by Anisian breccia. The ...overlying pelagic Anisian and Ladinian strata with pyroclastic rockscan be interpreted as a result of rift tectonics of Adria micro-plate. A 500 m thick sequence is capped by an emersion surface by karstification and terrigenous sediments including conglomerate as a result of Late Triassic transgression and marking the lower boundaryof a new, Late Mesozoic, megasequence of the External Dinarides.By means of conodont study, in the lowermost part of the studied Mesozoic sequence, a Lower Triassic shallow-water conodont fauna yielding Pachycladina obliqua apparatus was recorded. Pelagic limestone beds overlying the »Otarnik breccia« are marked byconodont elements of the Anisian constricta Zone. The Ladinian interval is characterized (from bottom to top): trammeri A. Z., hungaricus A. Z. and mungoensis A. Z. The uppermost part of the section below the emersion surface is identified by Pseudofurnishiusmurchianus, indicating the Upper Ladinian-Lower Carnian murchianus Zone.
Učkarski zvončić (Campanula tommasiniana) je stenoendem planine Učke, koji se rasprostire na području od svega 6 do 7 km2 u pojasu između 50 i 1396 m nadmorske visine. Unutar areala ove vrste uočeno ...je pet uglavnom homogeno nastanjenih mikrolokaliteta. Veći dio populacije vrste uspijeva u pukotinama stijena i litica iznad 900 m n.m., unutar pojaseva klimazonalne termofilne te altimontanske i subalpinske šume bukve, iako su pojedini primjerci često zabilježeni u različitim sekundarnim staništima duž cijelog areala. Uslijed nedostatnog poznavanja biologije, gustoće populacije, genetske strukture populacije i potencijalnog protoka gena unutar i između mikropopulacija učkarskog zvončića, teško je točnije pretpostaviti stupanj njegove ugroženosti. Međutim, uništavanje primarnih staništa ovog stenoendema izrazito točkastog (diskontinuiranog) areala, može predstavljati stvarnu prijetnju njegovu dugoročnom opstanku, te je stoga vrlo važno strogo čuvati sva ustanovljena i potencijal na staništa ove vrste.
Speleothems occurring in some caves of the carbonate Dinarides line all channel surfaces, and have been deposited from meteoric waters under phreatic conditions. Such phreatic speleothemic deposition ...modifies common experience (l) that meteoric phreatic conditions cause dissolutional widening of cave voids, and (2) that speleothems imply vadose conditions. The phreatic speleothems described here postdate an early polygenetic evolution of the cave voids, and predate the last, vadose stage. They were likely produced during the late/postglacial warming period, when dissolved carbonate was amply supplied, and when there was much water available for saturation of underground voids. Phreatic speleothems may be used as a tool for time correlation of internal deposits, both within one cave and within a karst region. They indicate an important stage in the history of the ground-water regime of an area. In general, phreatic speleothems help in better understanding of the development of subterranean voids and related karst/palaeokarst.
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IJS, IMTLJ, KILJ, KISLJ, NUK, SBCE, SBJE, UL, UM, UPCLJ, UPUK
During the last, Late Pleistocene-Holocene transgression, rising sea flooded a vast part of the Dinaric karst. Due to prevalence of carbonate rocks in the drainage area of most of the rivers on ...Eastern Adriatic coast, those rivers carry only approximately 20% of particulates as suspended matter and the rest is dissolved. Consequently, many typical karst features such as karrens, dolines, poljes, caves, pits and river valleys and canyons as well, presently under the sea, can still be recognized. Beside these simply drowned features, some new ones were formed by the sea level rise. Those are submarine springs, so called vruljas, brackish coastal springs and marine lakes. The most significant evidences of former subaerial conditions are speleothems in submerged caves and calc tufa deposits of drowned paleo rivers. Both of them could be used for determination of the former low sea level stands.
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