Alfred Vespremeanu-Stroe

• Professor
• Professor (Full) at University of Bucharest

A comprehensive analysis of data collected over the last five decades on the Danube delta coast (topographic maps, satellite imagery, GPS surveys and beach profiles) revealed two different shoreline dynamics patterns: (1) high mobility during 1961-1979 interval with high retreating and; (2) advancing rates and low mobility afterwards (1979-2006). T...

Beach–dune seasonal elevation changes, aeolian sand transport measurements, bathymetric surveys and shoreline evolution assessments were used to investigate annual and seasonal patterns of dune development on Sfântu Gheorghe beach, the Danube delta coast, from 1997 to 2004. Dune volume increased consistently (1.96 m3 m−1 y−1 to 5.1 m3 m−1 y−1) over...

The Southern Carpathians, a pivotal yet understudied transition zone between Atlantic and continental climate regimes, lack high-resolution summer temperature reconstructions critical for deciphering North Atlantic Oscillation (NAO) and North Atlantic Jet (NAJ)-driven Holocene climate variability. In this multi-proxy study, we use subfossil chirono...

Rock glaciers, composed of debris and ice, are widely distributed across cold mountain regions worldwide. Although research on rock glaciers is gaining momentum, the distinct behaviour of rock glaciers in the marginal periglacial environments remains poorly understood. In this study, we combine remote sensing and in situ methods to gain insights in...

River deltas ofer numerous ecosystem services and host an estimated global population of 350 million to more than 500 million inhabitants in over 100 countries. To maintain their sustainability into the future, deltas need to withstand sea-level rise from global warming, but human pressures and diminishing sediment supplies are exacerbating their v...

River sediment supply (Qs) and longshore sediment transport (LST) are recognized as two paramount controls on river delta morphodynamics and stratigraphy. We employed the Delft3D model to simulate the evolution of deltas from fluvial to wave‐dominated conditions, revealing the interplay between river‐ and wave‐driven sediment quantities. Wave‐influ...

Computer modeling of sporadic and isolated patches of mountain permafrost distribution is difficult to implement without overestimating it. The main challenge is to determine the very areas where the criteria for permafrost maintenance are met. This paper aims to modeling the permafrost distribution in the Southern Carpathians (SC), a typical margi...

This study reconstructs the paleoecological settings of Chilia/Licostomo, the most important Genoese colony in the Danube delta. Our paleoenvironmental data (i.e., sedimentology, pollen, charcoal, radiocarbon ages) corroborate historical and archaeological information over the last seven centuries to document the habitation at Chilia and its milita...

Rock walls in high mountain areas are the expression of long–term slopes response (10³–10⁵ years) to tectonics, weathering and denudation and a major source of sediment and hazard. Controls of mountain rock walls (RW) distribution and the response to post-glacial evolution are rarely discussed in the literature at the scale of mountain ranges. Usin...

We constructed a high-resolution Bayesian sedimentation model spanning the last 5500 years based on 25 AMS radiocarbon dated sediments of bulk organic matter (OM) sampled from the NW Black Sea anoxic waters of the continental slope. The corrections for the ¹⁴C ages due to marine reservoir effect (MRE) and detritus organic carbon are correlated with...

Vegetation is an important ecological indicator of rock glaciers' activity as its development marks the transition from active to inactive and relict states. Most rock glaciers in Retezat Massif are covered by vegetation, mostly Pinus mugo shrubs but also herbaceous and forestry vegetation. In this paper, 82 rock glaciers from Retezat are classifie...

At river mouths, fluvial jets and longshore currents (LSCs) generated by waves interact hydrodynamically. This idealized numerical modeling study simulates a large number of hydro-morphodynamic conditions (650) to explore the emergent hydrodynamics determined by different mouth bar volumes and geometries, river discharge, wave heights, and directio...

This paper documents the Late-Holocene environmental changes and human presence in the northern Danube delta using a multidisciplinary approach that combines geoscientific data with archaeological findings, historical texts, and maps. It follows the formation and progression of the Chilia distributary and the reconfiguration of socioeconomic activi...

Casimcea Plateau is an uplifted (exhumated) peneplain cut in Proterozoic green-schists and one of the oldest tec-tonic units around the Black Sea. Despite its overall monotonous physiognomy, the plateau is crossed by Casimcea Valley and presents a seaward façade to the east which preserves (sub)horizontal surfaces as testimonies of the paleoenviron...

River floodplains are amongst the most dynamic features which are continuously changing their shape and structure in relation to climate, vegetation, human pressure and base-level variability. In this study, we focus on the lower reach of Danube (upstream of its delta) and investigate the formation and transformations of wetlands and lakes during t...

The Black Sea basin is a unique and very complex environment in the World Ocean as a result of its evolution, location and history. This is the reason why in the last years there is an increasing scientific interest in deciphering the processes and mechanisms governing this area. Besides the well-known environmental problems of the basin related to...

This study proposes a local paleo-reconstruction of the Danube floodplain based on the multiproxy analysis of an 8 m core extracted from Lake Brateș. Due to lacustrine sediments sensitivity to changes in the surrounding area we chose Lake Brates which through its position within the Lower Danube valley is a proxy for the evolution of Cotul Dunării...

We document a case of exceptionally large natural breaching of a sandy spit (Sacalin spit, Danube Delta) using multiannual to seasonal surveys of topography and bathymetry on successive cross‐barrier and shoreface profiles, LiDAR data, satellite imagery, and wind and wave data. The large breach, which quickly reached 3.4 km in May 2014, is attribut...

This study proposes a local paleo-landscape reconstruction of the Danube floodplain based on a stratigraphic sequence retrieved from Brateș Lake which, by its emplacement near the confluence of Danube-Prut rivers, was fully receptive to changes associated to hydrological, geomorphological or anthropogenic driven events. Due to its intermediate posi...

Archaeological data provide evidence of human inhabitation in the Danube Delta since the Early Neolithic with once flourishing human settlements such is the case of Enisala and Babadag settlements. Their remains dating back from Eneolithic (Enisala) or Iron Age (Babadag) or from their revivals in Antiquity and Medieval Age have been found on higher...

Mountain rockwalls (RW) dynamics is modulated by (thermal) weathering patterns and intensity and, in the same time, experience a strong structural and lithological control. This work presents the inventory and morphometric analysis of ca. 800 rockwall surfaces in the formerly glaciated Romanian Carpathians (44 • 30'-47 • 45' N, 21 • 30'-27 • 10' E)...

Annual and seasonal bathymetric measurements at the Saint George river mouth and numerical modelling show the role of storms and floods in river mouth bar morphodynamics.

Ground and air temperature monitoring, geophysical soundings and dendrological investigations were applied to a basaltic talus slope–rock glacier system from Detunata site in the Apuseni Mountains (Western Romanian Carpathians) to verify the presence of sporadic permafrost at 1020–1110 m asl, well below the regional limit of mountain permafrost. Th...

This paper presents an overview of storminess along the Danube delta coast since 1949 by analysing wind and wave data and discusses the influences of teleconnections on climate variability. To this end, a five-category storm classification is proposed based on wind speed intensity and storm duration. On average, this coast experiences 30 storms/yea...

Danube Delta coastline evolution showed a significant variability in the past 150 years related to different driving forces which change the leading role between them depending on the temporal and spatial scales taken into consideration. At long time scales (centuries), coastline dynamics is mainly driven by the dramatic decrease of Danube sediment...

The present Danube Delta shoreface morphology (in terms of longshore variability of cross-shore profile shape and slope) and behaviour (sediment distribution and transport, depth changes) reside from the co-existence of different types of accretionary, stable and erosive sectors. This configuration is the result of various controlling factors: the...

The study of past glaciations extent and chronology in the Romanian Carpathians has been of great interest for scientists in the last 135 years. In the last decade, in addition to the geomorphologic investigations, several studies presented numerous absolute age datings of the glacial deposits that improved considerably the knowledge on the last gl...

This chapter is devoted to the foredunes developed on the dry temperate Danube delta coast with a focus on the Sf. Gheorghe beach (Sărăturile ridge plain) at the updrift of the Sf. Gheorghe mouth. It presents the medium term (e.g. 17 years) beach–foredune dynamics and foredune morphology together with the alongshore variability pattern as influence...

Coastal storms hitting the Danube Delta coast are recurring high-energy events (of high winds and waves), which in most cases are the result of Mediterranean (extratropical) cyclones following different trans-Balkan routes. By using long-term wind (1962–2012) and wave (1949–2013) data, we investigated the climatology of storms and their impact on t...

Thermal weathering assessment is essential in establishing present and past rock surfaces dynamics in mountain areas. Though for the Romanian Carpathians most studies rely on air temperature when estimating the intensity of freeze-thaw cycles, comparative analysis of in situ ground thermal measurements shows that important differences occur in the...

The sporadic permafrost specific to the Southern Carpathians is accommodated in three main features at sites with commonly low solar radiation—(i) rock glaciers (>1950 m altitude), (ii) talus slopes, and (iii) shaded rock walls (>2400 m)—with a net prevalence of the former category. Due to its marginal character, the alpine permafrost in Southern C...

This chapter presents synthetically the latest progresses made on Danube Delta evolution based on new cores, sedimentological and morphological analyses which together with the newly obtained absolute ages (AMS 14C and OSL) shed a new light upon the delta formation in both its evolutionary phases (chronology) and the growth patterns. It is the firs...

New and innovative scientific theories, discussion and explanations are presented on landform dynamics and evolution in Romania along with a comprehensive understanding of the geomorphological processes shaping the large variety of Romania’s landscape. Thematically arranged the book deals with landform dynamics of specific relief types: glacial and...

We report on a 6-year nearshore bathymetric dataset from the Danube Delta (Romanian Black Sea coast) that comprises 16 km of erosive, stable and accumulative low-lying micro-tidal beaches northward of Sf. Gheorghe arm mouth. Two to three two-dimensional longshore sandbars exhibit a net multi-annual cyclic (2.8-5.5 years) offshore migration (20-50 m...

Weathering microforms associated with exfoliation were investigated on 40 granitic spheroidal boulders identified on Pricopan Ridge (Măcin Mountains) in order to establish a spatial distribution pattern. Continuous thermal monitoring allowed the frequency and intensity distribution assessment of short-term temperature changes triggered by summer st...

Danube delta, as most of the large deltas, favours complex interactions between river sediment supply and marine dispersing forces which create complex configurations with concurrent morphologies (i.e. river-versus wave-influenced) or processes (accretion versus erosion) and even distinct landscapes for the same accretionary features: strandplains...

This paper presents a comparison of evolution and dynamics of selected representative deltaic spits. Although recently receiving more attention, deltaic barrier spits still remain poorly understood in terms of long term evolution. Water, sediment and wave interactions at the river mouth are highly nonlinear such that hydrodynamic groin effects and...

Spits can emerge in different situations: -Under the emergence of bars on the very low slope of mouth bar platforms (crest), and are the result of a positive sedimentary budget in the front of the river mouth: Sacalin, Ba Lat, Kakinada. -In very acute wave angle conditions: Damietta, Krishna. -Under river mouth abandonment and lobe reworking: Ebro,...

The ventilated cold screes from the temperate regions develop high negative thermal anomalies (ground versus air annual temperature) in their lower parts due to cold air aspiration in wintertime, which support the formation of cold reservoirs and sometimes of the perennial frozen ground. Ground and air temperature monitoring, geophys-ical soundings...

The ventilated cold screes from the temperate regions develop high negative thermal anomalies (ground versus air annual temperature) in their lower parts due to cold air aspiration in wintertime, which support the formation of cold reservoirs and sometimes of the perennial frozen ground. Ground and air temperature monitoring, geophys-ical soundings...

Deltaic spits are among the most highly dynamic and vulnerable coastal landforms rapidly changing their dimension, plan position and morphology. Sacalin barrier spit formed at the southernmost Danube mouth (Sfântu Gheorghe arm), representing the youngest downdrift feature of the Sfântu Gheorghe deltaic lobe (1500 BP - present). Sacalin emerged in 1...

This chapter is about the sand spits formation, evolution and morphology at the Danube mouths, developed within the general framework of the virtually tideless Black Sea basin in a medium-wave energy environment. It deals with both barrier spits and islands, in respect to their processual development as most of the Danube delta spits derive from fo...

The geomorphological evidences along with the range of methods recently (since 2008) applied in the Romanian Carpathians indicate that most of the rock glaciers are relict or inactive in the present. Only a few cases of active or complex rock glaciers (active only across their upper parts) are supposed to exist in the highest granitic massifs of So...

The wave asymmetric Sf. Gheorghe lobe is the only active in the Danube delta where river mouth bar (and the associated barrier islands and spits) continuously deployed a cyclic development for almost two millennia. During first stage, the Sf. Gheorghe distributary had a small discharge (with an order of magnitude lower than present) which after tha...

Deltaic beach-dune systems are extremely dynamic, responding to processes operating on scales from short-term variations related to storm and floods to long-term evolution driven by large-scale sediment dynamics (including lobe switching). On Danube Delta beaches, coastal storms and associated processes lead to a wide range of morphological impacts...

Thermal and geoelectrical methods were used to detect permafrost in rock glaciers, block fields, talus slopes and rockwalls in the granitic alpine area of Parâng Mountains where large rock deposits exist above the timberline. Variability of debris porosity at different sites, with and without permafrost, was preliminary assessed by measuring the cl...

Air temperature is frequently used in frost weathering studies for the assessment of freeze-thaw cycle frequency and freezing intensity on different scales, although ground thermal behaviour is more relevant. In this paper we compare the estimations made by meteorological daily data with the results of continuous field measurements of air, soil and...

Histria (Istros) is one of the earliest Milesian colonies founded on the Black Sea coast during the archaic period (7th c. BC). Its remains are located within what is today the Razelm–Sinoe lagoon system which forms the southern part of the Danube Delta. During its 13 centuries of existence, Histria experienced an environment favourable for a prosp...

Histria (Istros) is a Milesian colony founded on the Black Sea coast during the 7th c.BC. Nowadays, the remains of the ancient city are located 8 km inland form the Black Sea coast, on the continental edge of the Razelm-Sinoe lagoon system which forms the southern part of the Danube Delta. Significant environmental changes occurred during and after...

Coastal foredunes, shoreline and nearshore sandbars compose one large-scale interactive morphological system. Although the variability of these coastal features and their connection to environmental factors have been the focus of many analyses, the direct interactions between them are yet poorly identified, especially for natural nontidal coasts. T...

The present study attempts to develop a comprehensive perspective of the wind regime on the Romanian territory, focusing on the characteristics and tendencies encountered over the past 50 years, as well as on the NAO projection on it, using several data categories gathered from 167 meteorological stations. Based on the recorded multiannual averages...

Thermal conditions in seven rock glaciers (RGs) in the Retezat Mountains were examined using ground surface temperature, the bottom temperature of snow (BTS) and late-summer water temperature at springs. Direct current resistivity profiles were used to detect ice-rich layers and to estimate RG volume. These parameters were supplemented by measureme...

Sf. Gheorghe arm is one of the three main distributaries of the Danube, forming a delta in the Black Sea. The mouth of Sf. Gheorghe is among the few large European river mouths that have been free of direct large-scale engineering works. However, channel cutting in the Danube delta since the 19th Century as well as intensive damming of the Danube a...

A comprehensive analysis of data collected over the last five decades on the Romanian Black Sea coast (meteo & hydrological data, sea level, topographic maps, satellite imagery, GPS surveys and beach profiles) demonstrate that the North-Atlantic Oscillation (NAO) exerts a multi-decadal influence on the Romanian Black Sea coastal environment compone...

Long-term, cyclic offshore migration is a common occurrence on many multiple-barred beaches. The inter-site variability of this behavior was documented to be related to differences in certain key geometric parameters. Besides the inter-site variability, there also appears to be considerable intra-site variability in sandbar behavior, factors contro...

Author Posting. © Akadémiai Kiadó, 2010. This is the author's version of the work. It is posted here by permission of Akadémiai Kiadó for personal use, not for redistribution. The definitive version was published in Acta Geodaetica et Geophysica Hungarica 45 (2010): 71-79, doi:10.1556/AGeod.45.2010.1.11. From 1856 to 1939, the European Commission o...

Textural parameters are regarded as precious informational source for the genesis and evolution of coastal sedimentary environments. The purpose of this paper is to give a detailed insight of the grain size, sorting and skewness of sediments from the beach-dune system as well as to establish the relationships between them, the local characteristics...

This work addresses the thermal behavior of the rock surface in two mountain sites with different, rather extreme climatic conditions. As thermal weathering is one of the highly potential driving factors in mountain morphodynamics, the evaluation of the processes involved is utterly important. Freeze-thaw cycles (F-TC) typology and development and...

The largest dunefields in the Danube delta developed during the Late-Holocene on the Caraorman and Letea beach ridge plains. Our research focused upon the reconstruction of aeolian landforms in the Danube Delta. Field based investigations of the modern aeolian morphology revealed the succession of different aeolian activity phases shaping the moder...

The largest dunefields in the Danube delta developed during the Late-Holocene on the Caraorman and Letea prograded barriers. The sand dunes in the Danube delta are one of the most pristine coastal dunes in Europe. Our research focused upon the reconstruction of aeolian landforms in the Danube delta. Field based investigations of the modern aeolian...

The present study aims to provide new and precise data regarding the glacial lakes morphology from Southern Carpathians. Based on detailed bathymetric surveys, this paper analyses morfometric and morphological characteristics of glacial lakes and compares them with previous results. The comparative analysis of the morphometric parameters analys...

In the international literature there are just a few works which deal with the multiannual dynamics of nearshore bars on the Earth coasts and no one for the virtually tideless beaches. Based on the seasonal bathymetric surveys this paper examines the overall three years morphodynamics of Sfantu Gheorghe submerse shore focusing on the nearshore b...