Cave levels and cave development in the Mitchell Plain following base-level lowering
Carbonate rock ; Drainage ; Fault ; Indiana ; Karst ; Karstification ; Piezometric level ; United States
The response of two adjacent cave systems to a single phase of valley entrenchment is examined here. The caves developed at different distances from the East Fork of the White River, the principal drainage and control on baselevel in the central
portion of the Mitchell Plain. They display multiple levels and distinct passage morphologies, which, it is argued, illustrate their particular reaction to base-level lowering.
Analyse numérique ; Fluviatile ; Hydrologie fluviale ; Modèle ; Niveau de base
The AA. investigate river profile response to continuous baselevel drops using a computer model. In the analysis of results, they pay particular attention to indicators of headwaters erosional response to this type of baselevel change.
The declining but non-rejuvenating baselevel. The Lisan Lake, the Dead Sea area, Israel
Cône alluvial ; Domaine aride ; Fluviatile ; Géographie physique ; Géomorphologie climatique ; Israël ; Mer Morte ; Niveau de base ; Terrasse fluviatile
The study area is an entrenched fan delta with a sequence of 14 unpaired fan terraces which die out at intersection points within an alluvial fan system. The results suggest that the intersection points did not function as baselevels. The receding
baselevel played only a passive role, allowing entrenchment without transmitting a head-cutting feedback basinwards. The arid environment caused a delay in transmission of information through the system. It is suggested that baselevel effects
The role of base-level change in the dissection of alluvial fans : case studies from southeast Spain and Nevada
Alluvial cone ; Almería ; Andalusia ; Baselevel ; Climatic variation ; Comparative study ; Eustatism ; Fluvial processes ; Geomorphometry ; Mountain ; Nevada ; Quaternary ; Spain ; United States of America
Almería ; Andalucía ; Cône de déjection ; Espagne ; Etats-Unis ; Etude comparée ; Eustatisme ; Fluviatile ; Géomorphométrie ; Montagne ; Nevada ; Niveau de base ; Quaternaire ; Variation climatique
This paper examines the response of dry-region alluvial fans to base-level change. After a brief discussion of tectonically induced base-level change, this paper deals with climatically induced base-level change, and how its effect interact
Erosion ; Géomorphodynamique ; Modèle ; Niveau de base ; Profil longitudinal ; Ravinement ; Ruissellement ; Simulation
into stability. Three scenarios were used : gully evolution is controlled by initial topography and texture, when the discharge and baselevel are constant; discharge is constant and the baselevel lowers over time; the baselevel is constant and the discharge
This report briefly reviews the IPCC Fourth Assessment Report (AR4) sea-level summary and projections for future change. It then considers the development of high-resolution records of relative sea-level (RSL) change which have the potential
to bridge the gap between instrumental data and longer geologically based reconstructions.
late Cenozoic landform development in East Africa: the role of near baselevel planation within the dynamic etchplanation concept
Africa ; Baselevel ; Cenozoic ; Concept ; Eastern Africa ; Fluvial dynamics ; Geomorphogenesis ; Planation ; Rift ; Tectonics ; Vertical movement
Afrique ; Afrique de l'Est ; Aplanissement ; Concept ; Cénozoïque ; Dynamique fluviale ; Géomorphogenèse ; Mouvement vertical ; Niveau de base ; Rift ; Tectonique
near baselevel. It is therefore proposed to elaborate the etchplanation concept with fluvial dynamics. Late Cenozoic planation events in East Africa were triggered by a major baselevel rise due to the combined effects of eustatic sea level rise
Fluvial adjustment of the Lower Jordan River to a drop in the Dead Sea level
Asia ; Channel geometry ; Dead Sea ; Downcutting ; Israel ; Jordan ; Longitudinal section ; Meander ; River bed ; Sea level ; Southwest Asia ; Stream
This paper examines the effects of baselevel lowering on the channel morphology of the southern end of the Lower Jordan River. The recent chronology and rate of channel changes through the lower reach of the river caused by the lowering of the base
level, changes in the longitudinal profile and channel planform, are documented.
Almería ; Bassin-versant ; Capture fluviale ; Cours d'eau ; Espagne ; Mouvement vertical ; Niveau de base ; Quaternaire ; Réseau de drainage ; Tectonique
in the region. Resulting base-level changes in the affected area reached a maximum of ca. 90 m at the point of capture. The complex evolution of the drainage networks since the base-level change will be traced using a combination of evidence from the geological
Late Holocene sea-level change on Rota and Guam, Mariana Islands, and its constraint on geophysical predictions
C 14 dating ; Geophysics ; Holocene ; Micronesia ; Model ; Quaternary ; Reef ; Sea level ; Vertical movement
Holocene emergent reefs and notches are well distributed on Rota and Guam. Relative sea-level changes at these islands are reconstructed based on geomorphological observations and borings on present and emergent reefs, together with 54 radiocarbon
dates. Reconstructed late Holocene sea-level change in the Mariana Islands provides constraints on geophysical models of sea-level variations.
The water level simulation for optimization of crane habitat in Xianghai wetland is based on the grid analysis modular of GIS, so it needs not only topographic information but also the landscape type information. In this paper, the effect on reed
distribution scopes and reed area when the water level changes are discussed, as well the threshold value of water level when the reed area is the maximum.
Rates of sea level rise for southern New England : a space-time concept
An application of trend surface analysis is presented within a spacetime framework to predict the rates of sea-level rise for the southern New England coastal region since 10,000 years B.P. Based on the predicted second order trend surface, 65
% of the variance is explained and is significant at the 0,01 level.
in the development of the soils and landscape. Based on ages and heights above the mean sea level for the 5 terraces recognized in the study area, the overall base-level rise rates are calculated for the mainland (Jaldi anticline). These baselevel changes represent
This study attempts investigations of geomorphology and soils of a part of coastal area of Bangladesh, and to work out the role of different pedogenic processes, neotectonic activities (folding), and Late Quaternary climate/sea-level fluctuations
combined effects of eustatic sea level and tectonic uplift due to folding.
DEM based examination of pediment levels: a case study in Bükkalja, Hungary
of the pediment. Applying different GIS based methods, the height and location of these levels were determined and their area calculated as well. Relationship was established between the location of the upper pediment level and the occurrence of welded ignimbrites
Bükkalja is the southern pediment of Bükk Mountains. According to the geographic literature this area is divided into two pediment (geomorphic) levels. Using the methods of quantitative geomorphology, the Bükkalja pilot area was examined
in the paper. The main objectives of the investigation were the validation of examinations based on the digital elevation model by the accepted scientific achievements, and the analysis of the role of Miocene welded ignimbrite cuestas in the evolution
This paper focuses on the simulation of theoretical cases to determine, in a purely speculative way, what and how many different types of geomorphological effects are produced by a variable sea level, especially in the case of interaction
Bed-level adjustments in the Arno River, central Italy
Baselevel ; Carrying capacity ; Channel geometry ; Cross section ; Grain size distribution ; Human impact ; Hydraulic works ; Italy ; Stream
Action anthropique ; Aménagement hydraulique ; Arno ; Capacité de charge ; Cours d'eau ; Granulométrie ; Géométrie hydraulique ; Italie ; Niveau de base ; Profil transversal
This bed-level adjustment analysis identified the existence of 2 main phases of lowering : the first, triggered at the end of the past century; the second, triggered in the interval 1945-1960 and characterized by more intense degradation
Lake Michigan beach-ridge and dune development, lake level, and variability in regional water balance
Aerial photography ; C 14 dating ; Dune ; Holocene ; Lake ; Lake level ; Michigan ; Palaeoclimatology ; Quaternary ; United States of America ; Water balance
, and finally provides an interpretation of lake-level and regional climate history based on dune morphology and the radiocarbon chronology of ridge formation.
This paper reports the results of AMS radiocarbon dates of plant macrofossils associated with dune formation and growth, determines the historical relationships among beach-ridge formation, lake-level fluctuation, and regional climatic variation
Reconstruction of Holocene precipitation patterns in Europe using pollen and lake-level data
Europe ; Holocene ; Lake level ; Model ; Palaeoclimatology ; Palaeogeography ; Palynology ; Precipitation ; Quaternary
Lake-level data can be used to refine paleoclimate reconstructions based on pollen data. This approach is illustrated for the European Holocene. Reconstructions of temperature and precipitation are presented here for 9000, 6000, and 3000 yr B.P
. The maps demonstrate that a substantial improvement in quantitative palaeoclimate estimation can be achieved by using pollen and lake-level data in combination.
Implications of the radiocarbon timescale for ice-sheet chronology and sea-level change
C14 dating ; Deglaciation ; Geochronology ; Glaciation ; Global change ; Ice sheet;Ice cap;Inlandsis ; Isostasy ; Model ; Palaeo-environment ; Quaternary ; Sea level
A new extended radiocarbon calibration curve has allowed a reexamination of relative sea-level data based on pre-Holocene dates. At sites locates far from any Late Pleistocene ice sheet, the effect of employing this new calibration curve
is that the calibrated data now agnee with the corresponding relative sea-level curve predicted by the ICE-3G deglaciation model.
Available paleosea level traces continue to depend on deep-sea stratigraphy for confirmation rather than the reverse. Inferred initial sea levels, based on uplift assumptions or SO determinations on coral and mollusca, show considerable divergence
but broadly agree that sea levels assigned to isotope stages 5a and 5c were lower than today. Systematic studies should be expanded in environments that allow lithostratigraphic resolution of interdigitated marine and continental sediments, meticulously