Uplift-based limits to the thickness of ice in the Lake Agassiz basin of North Dakota during the Late Wisconsinan

Brevik, Eric C.; Reid, John R.

doi:10.1016/s0169-555x(99)00093-8

Cited by 5 publications

(7 citation statements)

References 32 publications

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“…Because the mantle's response to ice sheet loading has a response time of only 3 -4 ka [e.g., Le Meur and Huybrechts, 1996;Peltier, 1998], our isostatic approximation is reasonable. During ice sheet retreat a lithospheric rebound is considered underneath the ice by setting b = 0.225 which corresponds to a restrained rebound of 75% of the maximum depression which is in accordance with field data [e.g., Brevik and Reid, 2000]. The restrained rebound phase is followed by postglacial rebound during which we did consider a transient response empirically since postglacial rebound is incorporated as an exponentially decaying uplift rate (v pg [m/a]) following:…”

Section: Lithospheric Flexurementioning

confidence: 99%

“…A rigorous treatment of transient ice sheet flexure requires accounting for viscous mantle flow at the continental‐scale and the magnitude of flexure is largely controlled by the viscosity of the mantle underlying the lithosphere [e.g., Peltier , 1998]. The maximum isostatic deflection of the lithosphere by an ice load should be about 30% of the ice sheet thickness [e.g., Brevik and Reid , 2000; Howell et al , 2000]. Although the response of the lithosphere to ice sheet loading is transient with a response time of ∼3–4 ka [e.g., Le Meur and Huybrechts , 1996; Peltier , 1998], here, we employ an isostatic approach during ice loading and unloading.…”

Section: Processes Impacting Subsurface Fluid Flow During Glacial Cyclesmentioning

confidence: 99%

“…Field studies indicate that during ice sheet retreat the great majority of the isostatic rebound (e.g., 75% of the maximum deflection) happens while the ice is thinning during retreat [e.g., Brevik and Reid , 2000]. After this phase of “restrained” rebound, the remaining topographic depression (now about 25% of the maximum deflection) will be reduced through “postglacial” rebound.…”

Section: Processes Impacting Subsurface Fluid Flow During Glacial Cyclesmentioning

confidence: 99%

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Transient hydrodynamics within intercratonic sedimentary basins during glacial cycles

2008

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[1] The hydrodynamic consequences of a glaciation/deglaciation cycle within an intercratonic sedimentary basin on subsurface transport processes is assessed using numerical models. In our analysis we consider the effects of mechanical ice sheet loading, permafrost formation, variable density fluids, and lithospheric flexure on solute/isotope transport, groundwater residence times, and transient hydraulic head distributions. The simulations are intended to apply, in a generic sense, to intercratonic sedimentary basins that would have been near the southern limit of the Laurentide Ice Sheet during the last glacial maximum ($20 ka B.P.), such as the Williston, Michigan, and Illinois basins. We show that in such basins fluid flow and recharge rates are strongly elevated during glaciation as compared to nonglacial periods. Furthermore, our results illustrate that steady state hydrodynamic conditions in these basins are probably never reached during a 32.5 ka cycle of advance and retreat of a wet-based ice sheet. Present-day hydrogeological conditions across formerly glaciated areas are likely to still reflect the impact of the last glaciation and associated processes that ended locally more than 10 ka B.P. Our results reveal characteristic spatial patterns of underpressure and overpressure that occur in aquitards and aquifers, respectively, as a result of recent glaciation. The calculated emplacement of low salinity, isotopically light glacial meltwater along basin margins is roughly consistent with observations from formerly glaciated basins in North America. The modeling presented in this study will help to improve the management of groundwater resources in formerly glaciated basins as well as to evaluate the viability on geological timescales of nuclear waste repositories located at high latitudes.

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Section: Lithospheric Flexurementioning

confidence: 99%

Section: Processes Impacting Subsurface Fluid Flow During Glacial Cyclesmentioning

confidence: 99%

Section: Processes Impacting Subsurface Fluid Flow During Glacial Cyclesmentioning

confidence: 99%

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Transient hydrodynamics within intercratonic sedimentary basins during glacial cycles

2008

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“…67 After ice sheet recession, marine transgression caused by glaciation and flooding of this region is expected. 62 Calculations showed that water layer depth after flooding depended on the height of the ice sheet height, 68 asthenosphere. 69 In particular, the calculations were carried out for flooding of 5,000 and 2,500 years duration, respectively, and following subaerial conditions.…”

Section: During Periods Of Glaciation the Earth's Crust Bends Under Icementioning

confidence: 99%

Modeling thermal regime and evolution of the methane hydrate stability zone of the Yamal peninsula permafrost

Arzhanov

Malakhova

Мохов

2020

Permafrost & Periglacial

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In recent years, new geophysical phenomena have been observed in the highlatitude regions of continental permafrost. Since 2014 new craters 10-20 m in diameter have been found within the Yamal Peninsula and neighboring regions. They are associated with the emissions of gases, which could have been formed during dissociation of relict gas hydrate deposits due to increases in soil temperature. This paper presents the results of numerical modeling of the thermal regime of permafrost in the north of Western Siberia with the assessment of methane hydrate stability zone under climate changes over the past 130,000 years. According to the results obtained, the upper boundary of the methane hydrate stability zone in Yamal could have reached the surface within the periods of glacial maxima (about 90,000 and 60,000 years ago). We show that at present in Yamal permafrost above the modern boundary of the stability zone, relic methane hydrates are likely to exist at depths of up to 100-150 m, they could have "survives" warming during the Holocene optimum about 6,000 years ago and remain in permafrost rocks under negative temperatures even under transgression and increased geothermal flux conditions.

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“…In contrast, during the glacial-interglacial transitions, the glaciers on the Haizi Shan would have retreated in response to the rising temperature. As the volume of the glaciers decreased to the critical value, the unloading resulting from the glacier melting would have caused isostatic crustal rebound, during which the energy for tectonic activity accumulated during the former glacial expansion would have been released (Andrews, 1968;Sigvaldason et al, 1992;Brevik and Reid, 2000;Motyka, 2003;Bridgland et al, 2010). As a result, rapid uplift would have occurred in the Haizi Shan region.…”

Section: Incision Of Terraces T5-t2mentioning

confidence: 99%

Late Quaternary fluvial terraces near the Daocheng Ice Cap, eastern Tibetan Plateau

Zhou

2014

Quat. res.

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The timing of terrace formation relative to the glacial–interglacial cycle and what factors control that timing, such as changes in climate and/or uplift, are controversial. Here we present a study of the terraces along the Yazheku River using electron spin resonance (ESR) dating and analysis of the sedimentary characteristics in order to establish the timing of terrace formation and to assess the forcing mechanisms that have been proposed. The Yazheku River flows in glacial trough leading from the Haizi Shan, on the eastern Tibetan Plateau. The range was uplifted during the Quaternary and repeatedly glaciated by ice caps. The four highest major terraces (T5, T4, T3, and T2) are the result of both climatic and tectonic influences. Strath terraces T5–T2 were created during Haizi Shan glacial expansions during MIS 16, 12, 6 and 3–4, respectively. The major aggradation phases of the four terraces occurred during the deglaciations at the ends of MIS 16, 12, 6, and 2. Down-cutting, which led to the generation of the four terraces, immediately followed the deposition of the T5–T2 gravel units. These incisions occurred during the transitions between MIS 16–15, MIS 12–11, MIS 6–5, and MIS 2–1.

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Uplift-based limits to the thickness of ice in the Lake Agassiz basin of North Dakota during the Late Wisconsinan

Cited by 5 publications

References 32 publications

Transient hydrodynamics within intercratonic sedimentary basins during glacial cycles

Transient hydrodynamics within intercratonic sedimentary basins during glacial cycles

Modeling thermal regime and evolution of the methane hydrate stability zone of the Yamal peninsula permafrost

Late Quaternary fluvial terraces near the Daocheng Ice Cap, eastern Tibetan Plateau

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