Lateglacial and Postglacial Faulting in the Russian Part of the Fennoscandian Shield

Николаева, С. Б.; Никонов, А. А.; Шварев, С. В.

doi:10.1017/9781108779906.018

Cited by 3 publications

(3 citation statements)

References 11 publications

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“…An ocean load was not considered here but becomes important when analyzing stress changes for areas close or beneath the ocean (H. Steffen et al., 2019). Glacially triggered earthquakes as identified in SSDS have been suggested though in areas to the southeast (east in simple model) of the ice sheet center which have been covered by ice at Last Glacial Maximum (Baltica, Poland, Karelia, northern Belarus; e.g., Bitinas et al., 2021; Nikolaeva et al., 2021; Pisarska‐Jamroży et al., 2021; H. Steffen et al., 2019). This area becomes unstable during deglaciation, which fits with the reactivation time of the suggested occurrence of glacially triggered earthquakes.…”

Section: Discussionmentioning

confidence: 99%

Reactivation of Non‐Optimally Orientated Faults Due to Glacially Induced Stresses

Steffen

2021

Tectonics

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The deformation due to an ice load is accompanied by displacement and stress changes. These stress changes are known to have created large‐magnitude earthquakes along pre‐existing faults during and after deglaciation of the Late Quaternary ice sheets. However, these so‐called glacially induced faults have been found to be not optimally orientated in their respective regional stress regime. Here, we analyzed the potential of non‐optimally orientated fault reactivation within a glacially induced stress field as well as changes of the stress regimes due to these additional stresses. A finite element model is used to estimate glacially induced stresses, which are then combined with background stress magnitudes. Non‐optimally orientated faults can be reactivated by glacially induced stresses within thrust‐, strike‐slip‐, and normal‐faulting stress regimes, but depending on their location with respect to the ice sheet and their orientation within the regional stress field. While faults with large variations of dip and strike outside of the ice sheet are prone to reactivation when the background stress field is a normal‐ or strike‐slip‐faulting stress regime, faults within a thrust‐faulting stress regime can also be reactivated within the ice margin during and after the deglaciation. Outside the ice margin, instabilities in a thrust‐faulting stress regime develop along the intermediate principal stress axis. Stress regime changes can occur for all background stress states. Finally, we find that certain conditions in a strike‐slip‐faulting stress regime can also explain the observed glacially induced thrust faults in Northern Europe.

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Section: Discussionmentioning

confidence: 99%

Reactivation of Non‐Optimally Orientated Faults Due to Glacially Induced Stresses

Steffen

2021

Tectonics

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“…Осадки аккумулировались в морских заливах, занятых в настоящее время крупными долинами рек благодаря привносу потока- ми талых вод больших масс обломочного материала (Евзеров, 2016). Следует отметить, что вся зона Мурманского берега сопряжена с крупным разломом Карпинского, вдоль которого фиксируется повышенная историческая и палеосейсмическая активность (Никонов и др., 2015; Nikolaeva et al, 2021). Эта структура разграничивает Баренцевоморскую (Свальбардскую) плиту и Балтийский щит.…”

Section: район исследований и объектыunclassified

“…Активное развитие палеосейсмогеологических исследований в последние десятилетия позволило выделить следы сильных древних землетрясений как в скальных породах, так и в рыхлых отложениях практически на всей территории Фенноскандии (Stewart et al, 2000;Morner, 2003;Николаева, 2006;Lagerbäck, Sundh, 2008;Kukkonen et al, 2010;Шварев, Родкин, 2017;Nikolaeva et al, 2021). Эти исследования изменили и существовавшие долгое время представления о генезисе многочисленных и разнообразных деформаций слоистости в четвертичных осадках, обнаруживающих не только гляциотектонические, мерзлотные, криогенные, и седиментационные признаки, но и следы прошлых сильных сейсмических воздействий.…”

Section: Introductionunclassified

Генезис И Условия Формирования Деформационной Слоистости В Позднеледниковых Отложениях Мурманского Побережья (СЗ Кольского Региона)

С.Б.¹

2023

Труды ФНС

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Аннотация. В ледниково-морских отложениях долины реки Ура (Мурманское побережье Кольского региона) было обнаружено шесть горизонтов со специфическими типами деформационных структур (SSDS). Они представлены отпечатками нагрузки, структурами пламени, осадочной брекчией, структурами выхода воды и явлениями ликвефакции. Детальный литологический анализ этих структур показал, что деформации были образованы в результате гравитационных потоков (обломочных и мутьевых) и разжижения. В пределах двух из шести слоев с SSDS также были обнаружены следы повторного разжижения. Предположительно триггером для образования горизонтов с деформациями были землетрясения и афтершоки, возникающие вслед за дегляциацией территории и активизация крупного разлома Карпинского, разграничивающего Баренцевоморскую плиту и Балтийский щит.

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Traces of Seismic Activity in the Lake Bottom Sediments of Eastern Fennoscandia

Николаева

2022

Geodin. tektonofiz.

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This paper presents the results of a study on traces of ancient earthquakes in the lake bottom sediments of eastern Fennoscandia (Kola region and Karelia). Based on the sediment cores from six lake basins located within large active structures of the region, consideration is being given to the most typical features of sedimentation affected by neotectonic movements of the Earth's crust. The data presented here provide lithological-stratigraphical, paleobotanical and chronometrical evidence for lakes. The paper causes and mechanisms of formation of seismic structures in bottom sediments and their distinction from deformations of another origin.Generalized earthquake history in provided an opportunity to organize the existing information on the time of paleoearthquake manifestations and distinguish three active periods in paleoseismicity. These are Late Glaciation-Early Holocene marked by the most rapid uplift after the retreat of the last ice sheet (13500-8100 cal yr BP), Middle Holocene (6800-6600 cal yr BP), and Late Holocene (3100-200 cal yr BP). The results of this study showed that the number and intensity of seismic events changed at different stages of sedimentation. Since the Younger Dryas, fault zones (or their segments) have been repeatedly activated. Combined with the data on paleoseismicity in adjacent parts of Fennoscandia, our studies indicate an irregular pattern of the Late Pleistocene-Holocene seismic activity in stable areas formerly covered by glaciers. The obtained data make further adjustments to the neogeodynamic and seismic estimates of intraplate areas.

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Lateglacial and Postglacial Faulting in the Russian Part of the Fennoscandian Shield

Cited by 3 publications

References 11 publications

Reactivation of Non‐Optimally Orientated Faults Due to Glacially Induced Stresses

Reactivation of Non‐Optimally Orientated Faults Due to Glacially Induced Stresses

Генезис И Условия Формирования Деформационной Слоистости В Позднеледниковых Отложениях Мурманского Побережья (СЗ Кольского Региона)

Traces of Seismic Activity in the Lake Bottom Sediments of Eastern Fennoscandia

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