Search results for " landform"

The north-eastern aeolian ‘European Sand Belt’ as potential record of environmental changes: A case study from Eastern Latvia and Southern Estonia

2016

Abstract The Latvian and Estonian inland dunes belong to the north-eastern part of the ‘European Sand Belt’ (ESB). These dunes are widely distributed over broad glaciolacustrine plains and Late Glacial alluvial deltas, considered to be potential sources for the aeolian material. Little is known about these aeolian sediments and their substratum; here we present a detailed sedimentary structural and textural characterisation together with a luminescence-based chronology. Through a comparison between grain-size, rounding of quartz grains and surface characteristics in medium/coarse (0.5–0.8 mm) sand, and the light mineral content, we found an alternation of aeolian and periglacial components.…

The Late Ordovician glacial sedimentary system of the North Gondwana platform.

2009

International audience; The Late Ordovician (Hirnantian) glaciation is examined through the North Gondwana record. This domain extended from southern high palaeo-latitudes (southeastern Mauritania, Niger) to northern lower palaeo-latitudes (Morocco, Turkey) and covered a more than 4000 km-wide section perpendicular to ice-flow lines. A major mid-Hirnantian deglaciation event subdividing the Hirnantian glaciation in two first-order cycles is recognised. As best illustrated by the glacial record in western Libya, each cycle comprises 2-3 glacial phases separated by ice-front retreats several hundreds kilometres to the south. From ice-proximal to ice-distal regions, the number of glacial surfa…

Paleoclimatic evolution of the Uvs Nuur basin and adjacent areas (Western Mongolia)

2000

Abstract The investigations presented in this paper focus on the shifts in Pleistocene glaciations and the geomorphic changes in landforms, as well as lake level changes and aeolian deposits of the last glacial–interglacial cycle, including the Holocene. Geomorphic evidence and high lake levels show that the climate was more humid before the last glacial maximum (LGM); however, at least one arid phase also occurred. During the second half of the LGM the climate was dry and cold, turning to wet and cold during the Late Glacial of the last Ice Age. Fluctuations in humidity and temperature occurred during the Holocene. Since about 2000 yr BP the impact of human activity has increased.

The role of the diagnostic areas in the assessment of landslide susceptibility models: a test in the sicilian chain

2011

Abstract The aim of the research was to verify and compare the predictive power of different diagnostic areas in assessing landslide susceptibility with a multivariate approach. Scarps, landslide areas (the union between scarp and accumulation zones) and areas uphill from crowns, for rotational slides, source or scarp areas and landslide areas, for flows, have been tested. A multivariate approach was applied to assess the landslide susceptibility on the basis of three selected conditioning factors (lithology, slope angle, and topographic wetness index), which were combined in a Unique Condition Unit (UCU) layer. By intersecting the UCU layer with the vector layer of the diagnostic areas, la…

La forma del rilievo terrestre e il problema della convergenza morfologica

2018

Argomento della presente relazione è la forma del ri-lievo terrestre. Il rilievo terrestre può essere raffigurato come un grande mosaico le cui tessere sono i versanti. Un versante può es-sere: o una superficie piana caratterizzata da una determinata espo-sizione e da una specifica inclinazione; oppure una superficie curva di tipo concavo o convesso. Ogni singolo versante è inoltre identificabile con una forma del rilievo ben definita, la cui genesi è riconducibile ad un processo morfogenetico peculiare. Ogni cambiamento nell’esposizione, nell’inclinazione o nella curvatura di un versante segna pertanto il passaggio a forme del rilievo di-verse. Complessivamente, tutti i processi morfogenet…

Peculiar wall channels connected to fault breccia in the Grotta di Entella gypsum cave (Western Sicily, Italy)

2010

Vegetation as a tool in the interpretation of fluvial geomorphic processes and landforms

2016

STOP 9: Upper Daugava spillway valley and associated gully network at Vasargelišķi

2014

KARST OF SICILY AND ITS CONSERVATION

2012

Preservation of modern and mis 5.5 erosional landforms and biological structures as sea level markers: A matter of luck?

2021

The Mediterranean Basin is characterized by a significant variability in tectonic behaviour, ranging from subsidence to uplifting. However, those coastal areas considered to be tectonically stable show coastal landforms at elevations consistent with eustatic and isostatic sea level change models. In particular, geomorphological indicators—such as tidal notches or shore platforms—are often used to define the tectonic stability of the Mediterranean coasts. We present the results of swim surveys in nine rocky coastal sectors in the central Mediterranean Sea using the Geoswim approach. The entire route was covered in 22 days for a total distance of 158.5 km. All surveyed sites are considered to…