scholarly journals Some effects of lateral heterogeneities in the upper mantle on postglacial land uplift close to continental margins

1997 ◽  
Vol 128 (1) ◽  
pp. 175-187 ◽  
Author(s):  
G. Kaufmann ◽  
P. Wu ◽  
D. Wolf
Keyword(s):  
Upper Mantle ◽  
Continental Margins ◽  
Land Uplift ◽  
Postglacial Land Uplift ◽  
Lateral Heterogeneities

scholarly journals Lake and mire isolation data set for the estimation of post-glacial land uplift in Fennoscandia

2020 ◽  
Vol 12 (2) ◽  
pp. 869-873
Author(s):  
Jari Pohjola ◽  
Jari Turunen ◽  
Tarmo Lipping
Keyword(s):  
Spatial Location ◽  
Land Uplift ◽  
Data Set ◽  
Dry Land ◽  
Archaeological Data ◽  
Complex Process ◽  
Postglacial Land Uplift ◽  
Data Points ◽  
Ice Retreat ◽  
Shoreline Displacement

Abstract. Postglacial land uplift is a complex process related to the continental ice retreat that took place about 10 000 years ago and thus started the viscoelastic response of the Earth's crust to rebound back to its equilibrium state. To empirically model the land uplift process based on past behaviour of shoreline displacement, data points of known spatial location, elevation and dating are needed. Such data can be obtained by studying the isolation of lakes and mires from the sea. Archaeological data on human settlements (i.e. human remains, fireplaces etc.) are also very useful as the settlements were indeed situated on dry land and were often located close to the coast. This information can be used to validate and update the postglacial land uplift model. In this paper, a collection of data underlying empirical land uplift modelling in Fennoscandia is presented. The data set is available at https://doi.org/10.1594/PANGAEA.905352 (Pohjola et al., 2019).

Postglacial Land Uplift and the Autonomous Åland Islands as a Demilitarized Zone

1998 ◽  
Vol 67 (3) ◽  
pp. 299-307
Author(s):  
Keyword(s):  
Land Uplift ◽  
Demilitarized Zone ◽  
Postglacial Land Uplift ◽  
A Minor ◽  
The Impact

AbstractThe impact of postglacial land uplift on the geographical extent of the demilitarized zone of the autonomous Åland Islands is discussed. Ambiguities and inconsistencies in the Åland Convention, on the order of nautical miles, are revealed; they are due not only to the land uplift itself, but also to unclear definitions of coordinates. Further complications are caused by disagreements between the autonomy boundary and the demilitarization boundary. Suggestions for solving the problems are given, including minor amendments and clarifications of the Åland Convention, and also a minor amendment of the Autonomy Constitution of Åland.

The effects of upper-mantle lateral heterogeneities on postglacial rebound

1986 ◽  
Vol 13 (4) ◽  
pp. 337-340 ◽  
Author(s):  
Roberto Sabadini ◽  
David A. Yuen ◽  
Mark Portney
Keyword(s):  
Upper Mantle ◽  
Postglacial Rebound ◽  
Lateral Heterogeneities

DEEP CRUSTAL STRUCTURE UNDER THE PLAINS AND ROCKY MOUNTAINS

1966 ◽  
Vol 3 (7) ◽  
pp. 937-945 ◽  
Author(s):  
E. R. Kanasewich
Keyword(s):  
Rocky Mountains ◽  
Upper Mantle ◽  
Vertical Motion ◽  
Rocky Mountain ◽  
The United States ◽  
Continental Margins ◽  
Low Velocity ◽  
Mountain System ◽  
Deep Crustal Structure ◽  
Small Roots

The Airy hypothesis of isostatic compensation is very useful in accounting for structural differences between oceans and the continental margins. However, within the continents the compensation mechanism becomes more complicated. The thickness of the crust under much of the plains in the United States and Canada is between 40 and 55 kilometers. Determinations of crustal thickness under the Rocky Mountains gives results between 30 and 50 kilometers. Although local mountain ranges may have small roots, the Cordilleran region does not have a crustal root when compared to the plains. It follows that a modified form of Pratt's hypothesis of isostasy must be applied to continental regions. The density of the upper mantle is then different under the plains from what it is under the Rocky Mountains. In the plains it appears that there is a broad conformity of the Precambrian basement surface and the Mohorovicic discontinuity. Therefore the cause of epeirogenesis must lie within the upper mantle, possibly at the level of Gutenberg's low-velocity layer. The crustal studies in the plains and mountains indicate that more consideration should be given to gravitational gliding tectonics in the development of the Rocky Mountain system, since it is possible that there was substantial vertical motion of large crustal blocks.

scholarly journals Using the Nordic Geodetic Observing System for land uplift studies

2014 ◽  
Vol 6 (1) ◽  
pp. 377-401
Author(s):  
M. Nordman ◽  
M. Poutanen ◽  
A. Kairus ◽  
J. Virtanen
Keyword(s):  
Upper Mantle ◽  
Data Availability ◽  
Tide Gauges ◽  
Land Uplift ◽  
Mantle Dynamics ◽  
Quaternary Climate ◽  
Regional System ◽  
General Data ◽  
Different Sources ◽  
Observing Systems

Abstract. Geodetic observing systems have been planned and developed during the last decade. An ideal observing system consists of a network of geodetic observing stations with several techniques at the same site, publicly accessible databases, and as a product delivers data time series, combination of techniques or some other results obtained from the datasets. Globally, there is the IAG GGOS (Global Geodetic Observing System), and there are ongoing attempts to create also regional observing systems. In this paper we introduce one regional system, NGOS (Nordic Geodetic Observing System) hosted by the Nordic Geodetic Commission (NKG). Data availability and accessibility are one of the major issues today. We discuss on general data-related topics, and introduce a pilot database project of NGOS. As a demonstration of the use of such database, we apply it for postglacial rebound studies in the Fennoscandian area. We compare land uplift values from three techniques, GNSS, tide gauges and absolute gravimeter, with the Nordic NKG2005LU land uplift model. The purpose is to evaluate the data obtained from different techniques and different sources and get the most reliable values for the uplift using publicly available data. It is also important to consider the relation between geodetic observing systems and specific projects like DynaQlim (Upper Mantle Dynamics and Quaternary Climate in Cratonic Areas) or EPOS (European Plate Observing System). The natural aim of observing systems will be to produce data and other products needed by such multidisciplinary projects, but their needs may currently exceed the scope of an observing system. We discuss what requirements the projects pose to observing systems and their development.

scholarly journals GEODETIC EVIDENCE FOR ACTIVE UPLIFT OF THE OLYMBUS MT, GREECE

2004 ◽  
Vol 36 (4) ◽  
pp. 1697 ◽  
Author(s):  
S. Stiros ◽  
P. Triantafillides ◽  
A. Chasapis
Keyword(s):  
Upper Mantle ◽  
Small Amplitude ◽  
Engineering Geology ◽  
Local Instability ◽  
Land Uplift

Repeated leveling data collected between 1964-1989 along a traverse crossing the Tempi Valley and the Olymbus Mt (Greece) domai uplift testify to a small, though significant (4-21 ±1.2- 4.7mm) bulging of the central part of the traverse relative to its edges. In combination with coastal observations indicating land uplift at the eastern part of the traverse, as well as with structural and engineering geology observations excluding the possibility the overall pattern of observed displacements to reflect local instability effects, leveling data probably indicate a small amplitude domai uplift. The later is likely to reflect the continuation of the process responsible for the formation of the Olymbus-Ossa Mts, for uncovering of upper mantle rocks and for the impressive incision in the Tempi Valley. Furthermore, the lack of seismicity during the period covered by leveling data indicates that the Olymbus uplift is at least partly associated with aseismic processes.

Numerical simulation of asthenospheric flow around cratonic keels

2020 ◽  
Author(s):  
Edgar Santos ◽  
Victor Sacek
Keyword(s):  
Upper Mantle ◽  
Numerical Models ◽  
Relative Displacement ◽  
Planetary Science ◽  
Small Scale ◽  
Time Interval ◽  
Mantle Flow ◽  
Continental Margins ◽  
Thermochemical Convection ◽  
Synthetic Models

<p>In this work, we studied the mantle flow around cratonic keels using numerical models to simulate the thermochemical convection in the terrestrial mantle taking into account the relative displacement between the lithosphere and asthenosphere. The numerical simulations were performed using the finite element code developed by Sacek (2017) to solve the Stokes Flow for an incompressible Newtonian fluid. Several synthetic models in 2D and 3D were constructed considering different keel geometries and different regimes of relative displacement between the lithosphere and asthenosphere. In the present numerical experiments, we adopted a rheology in which the viscosity of the mantle is controlled by temperature, pressure and composition, assuming that the cratonic keel is compositionally more viscous than the surrounding asthenosphere, using a factor f to rescale the lithospheric viscosity compared to the asthenospheric one. We tested different f values, reference viscosity for the asthenosphere, and relative velocity between the lithosphere and the base of the upper mantle, quantifying the amount of deformation of the cratonic keel in each scenario. In general, we conclude that for a relatively low compositional factor (f < 20), the lithospheric keel can be significantly deformed in a time interval of few tens of million years when the lithosphere is moving horizontally relative to the base of the upper mantle, does not preserving its initial geometry. The synthetic models can be helpful for a better understanding of the interaction in the lithosphere-asthenosphere interface such as the deformation and flow patterns in the mantle around the keels, the rate of erosion of the root of the continental lithosphere due to the convection in the upper mantle and how it affects the thermal flow to the surface.</p><p>Sacek, V. (2017). Post-rift influence of small-scale convection on the landscape evolution at divergent continental margins. Earth and Planetary Science Letters, 459, 48-57.</p>

Upper mantle lateral heterogeneities and magnetotelluric daily variation data

1987 ◽  
Vol 125 (2-3) ◽  
pp. 319-340 ◽  
Author(s):  
J. L. Counil ◽  
M. Menvielle ◽  
J. L. Le Mouel
Keyword(s):  
Upper Mantle ◽  
Daily Variation ◽  
Variation Data ◽  
Lateral Heterogeneities
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