scholarly journals On deglaciation-induced perturbations of the geoid

1986 ◽  
Vol 23 (2) ◽  
pp. 269-272 ◽  
Author(s):  
Detlef Wolf
Keyword(s):  
Theoretical Model ◽  
Glacial Lake ◽  
Lake Levels

The importance of geoid perturbations in interpreting tilts of glacial lake levels is investigated, using a representative theoretical model. It is shown that near the ice margin, the slope of the Earth's perturbed surface is everywhere large compared with the slope of the associated undulation of the geoid. Perturbations of the geoid may therefore be neglected in interpretations of glacial strandline tilt.

The Cabot Head Archipelago: evidence of glacial Lake Algonquin on the Northern Bruce Peninsula, Ontario

2012 ◽  
Vol 49 (4) ◽  
pp. 576-589 ◽  
Author(s):  
Philip S.G. Kor ◽  
Daryl W. Cowell ◽  
Paul F. Karrow ◽  
F.J. Rik Kristjansson
Keyword(s):  
Great Lakes ◽  
Sea Level ◽  
Glacial Lake ◽  
Main Stage ◽  
Structural Factors ◽  
Lake Levels ◽  
Great Lakes Basin ◽  
Niagara Escarpment ◽  
Lake Algonquin ◽  
Glacial Lake Algonquin

The occurrence of abandoned shoreline bedrock erosional features at the edge of the Niagara Escarpment at Cabot Head indicates the existence of a group of islands in glacial Lake Algonquin during early postglacial time, referred to herein as the Cabot Head Archipelago. The abandoned shoreline features are situated as much as 80 m above the level of contemporary Georgian Bay. The range of abandoned shoreline bedrock erosional features, including shoreline cliffs, adjacent wave-cut platforms, wave-cut notches, shore stacks, shore caves, and other features, are described. The occurrence of these features is thought to be the result of the interaction between wave action in glacial Lake Algonquin and two distinct lithological facies representing the Wiarton – Colpoy Bay and Lions Head members of the Amabel Formation. The exceptional development of the abandoned shoreline bedrock erosional features in massive reefal dolostone between elevations of ∼250 and 255 m above sea level (asl) is interpreted as representing the relatively long-lived and stable Main stage of glacial Lake Algonquin (∼11 000–10 200 years BP). Shoreline erosional forms at elevations between ∼240 and 250 m asl may be indicative of declining lake levels partially controlled by bedrock structural factors. The final abandonment of the glacial Lake Algonquin shoreline in this area occurred when the eastern outlets of the lake became ice-free and its level dropped rapidly some 10 200 years BP. The Cabot Head Archipelago and the associated suite of raised and abandoned shoreline bedrock erosional features represent a rare assemblage of landforms within the Great Lakes basin, and possibly within Canada.

Glacial lake levels and Eastern Great Lakes Palaeo-Indians

2000 ◽  
Vol 15 (5) ◽  
pp. 415-440 ◽  
Author(s):  
Lawrence J. Jackson ◽  
Christopher Ellis ◽  
Alan V. Morgan ◽  
John H. McAndrews
Keyword(s):  
Great Lakes ◽  
Glacial Lake ◽  
Lake Levels

An analysis of the late glacial lake levels within the western Lake Superior basin based on digital elevation models

2013 ◽  
Vol 80 (3) ◽  
pp. 383-395 ◽  
Author(s):  
Andy Breckenridge
Keyword(s):  
Lake Michigan ◽  
Digital Elevation Models ◽  
Lake Superior ◽  
Late Glacial ◽  
Glacial Lake ◽  
Lake Levels ◽  
Lake Agassiz ◽  
Western Lake ◽  
Digital Elevation ◽  
Ice Retreat

This study establishes a detailed lake-level history for the Lake Superior basin by mapping strandlines from 10-m and 3-m digital elevation models. There are 24 levels above the mid-Holocene Nipissing level, and elevations increase along a direction of 23.1° due to post-glacial rebound. The highest level, the Epi-Duluth, is steeper than subsequent levels and may pre-date the Lake View ice advance into the western Lake Superior basin at the end of the Younger Dryas stade. The most prominent level is the Duluth, ca. 10,800 cal yr BP. Ice retreat exposed successively lower outlets, routing overflow to the Lake Michigan and Huron basins. By 10,600 cal yr BP, lake levels in the western Superior basin had dropped almost 200 m. This transformative period is complicated by multiple basin-wide events: the influx of glacial Lake Agassiz overflow, the creation of three sub-aqueous moraines, and a red to gray color transition in basin sediments. A later drawdown event has been hypothesized to have initiated the 9300 cal yr BP cooling event, but this flood was much smaller than estimated previously. If freshwater triggered the 9300 cal yr BP event, the source of the water must have been Lake Agassiz, not Lake Superior.

A Model for Analyzing Suicide Prevention

Crisis ◽  
2000 ◽  
Vol 21 (2) ◽  
pp. 80-89 ◽  
Author(s):  
Maila Upanne
Keyword(s):  
Risk Factors ◽  
Theoretical Model ◽  
Protective Factors ◽  
Suicide Prevention ◽  
Suicide Risk ◽  
Practical Work ◽  
Individual Risk ◽  
Self Assessment ◽  
Prevention Project ◽  
Individual Risk Factors

This study monitored the evolution of psychologists' (n = 31) conceptions of suicide prevention over the 9-year course of the National Suicide Prevention Project in Finland and assessed the feasibility of the theoretical model for analyzing suicide prevention developed in earlier studies [ Upanne, 1999a , b ]. The study was formulated as a retrospective self-assessment where participants compared their earlier descriptions of suicide prevention with their current views. The changes in conceptions were analyzed and interpreted using both the model and the explanations given by the subjects themselves. The analysis proved the model to be a useful framework for revealing the essential features of prevention. The results showed that the freely-formulated ideas on prevention were more comprehensive than those evolved in practical work. Compared to the earlier findings, the conceptions among the group had shifted toward emphasizing a curative approach and the significance of individual risk factors. In particular, greater priority was focused on the acute suicide risk phase as a preventive target. Nonetheless, the overall structure of prevention ideology remained comprehensive and multifactorial, stressing multistage influencing. Promotive aims (protective factors) also remained part of the prevention paradigm. Practical working experiences enhanced the psychologists' sense of the difficulties of suicide prevention as well as their criticism and feeling of powerlessness.

Do self-compassion and self-coldness distinctly relate to distress and well-being? A theoretical model of self-relating.

2018 ◽  
Vol 65 (3) ◽  
pp. 346-357 ◽  
Author(s):  
Rachel E. Brenner ◽  
David L. Vogel ◽  
Daniel G. Lannin ◽  
Kelsey E. Engel ◽  
Andrew J. Seidman ◽  
...  
Keyword(s):  
Theoretical Model ◽  
Well Being ◽  
Self Compassion
Sign in / Sign up

Export Citation Format

Share Document