Topic
Varve
About: Varve is a research topic. Over the lifetime, 1177 publications have been published within this topic receiving 40589 citations.
Papers published on a yearly basis
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Papers
TL;DR: In this article, stable-isotopic, geochemical, pollen and charcoal analyses were performed to find evidence of past regional climatic changes and human impact in the semi-arid region of eastern Anatolia, Turkey.
Abstract: Annually laminated sediments from Lake Van, spanning about 13000 varve years, were sampled for stable-isotopic, geochemical, pollen and charcoal analyses in order to find evidence of past regional climatic changes and human impact in the semi-arid region of eastern Anatolia, Turkey. The Lateglacial period was cold and dry, with steppe vegetation and saline lake water. During the Younger Dryas the lake level dropped dramatically, and the vegetation turned to a semi-desert. Geochemical and isotopic records indicate a strong increase in moisture at the onset of the Holocene, and Artemisia-chenopod steppes were partly replaced by grass steppe and pistachio scrub. A delay of about 3000 years in the expansion of deciduous oak woodlands and high steppe-fire frequencies suggest dry spring and summer weather during the early Holocene. At 8200 yr BP, a shift in the regional climate regime facilitated the transport of more moisture into the interior areas of the Taurus mountains and caused a change in the seasonal distribution of precipitation. The steppe-forests dominated by Quercus advanced and reached their maximum extention at about 6200 yr BP. All the proxy data indicate optimum climatic conditions, low water salinity and high lake level between 6200 and 4000 yr BP. After 4000 yr BP, aridity increased again and the modern climatic situation was established. Human impact in the catchment of Lake Van started at 3800 yr BP and was intensified during the last 600 years.
573 citations
TL;DR: In this article, a multidisciplinary approach is proposed to establish a varve chronology, which can be applied to precisely date events like volcanic ash layers, earthquakes or human impact, as well as short and long-term climate (temperature, precipitation, wind, hydroclimatic conditions or flooding) and environmental changes (eutrophication, pollution).
453 citations
TL;DR: In this paper, a study of the lower Van Normal reservoir after the 1971 San Fernando, California earthquake revealed three zones of deformational structures in the 1m-thick sequence of sediments exposed over about 2 km2 of the reservoir bottom.
439 citations
TL;DR: In this paper, a correlation and synchronisation of Weichselian Lateglacial varved lake sediments from western Germany (Meerfelder Maar, Eifel region), northern Germany (Hamelsee, Lower Saxony), central Poland ( Lake Gości a z) and eastern Poland (Lake Perespilno) by using varve chronology, tephrochronology, palynostratigraphy and stable isotopes was investigated.
342 citations
TL;DR: Two classes of field evidence firmly establish that late Wisconsin glacial Lake Missoula drained periodically as scores of colossal jokulhlaups (glacier-outburst floods) as mentioned in this paper.
Abstract: Two classes of field evidence firmly establish that late Wisconsin glacial Lake Missoula drained periodically as scores of colossal jokulhlaups (glacier-outburst floods). (1) More than 40 successive, flood-laid, sand-to-silt graded rhythmites accumulated in back-flooded valleys in southern Washington. Hiatuses are indicated between flood-laid rhythmites by loess and volcanic ash beds. Disconformities and nonflood sediment between rhythmites are generally scant because precipitation was modest, slopes gentle, and time between floods short. (2) In several newly analyzed deposits of Pleistocene glacial lakes in northern Idaho and Washington, lake beds comprising 20 to 55 varves (average = 30–40) overlie each successive bed of Missoula-flood sediment. These and many other lines of evidence are hostile to the notion that any two successive major rhythmites were deposited by one flood; they dispel the notion that the prodigious floods numbered only a few. The only outlet of the 2,500-km 3 glacial Lake Missoula was through its great ice dam, and so the dam became incipiently buoyant before the lake could rise enough to spill over or around it. Like Grimsvotn, Iceland, Lake Missoula remained sealed as long as any segment of the glacial dam remained grounded; when the lake rose to a critical level ∼600 m in depth, the glacier bed at the seal became buoyant, initiating underflow from the lake. Subglacial tunnels then grew exponentially, leading to catastrophic discharge. Calculations of the water budget for the lake basin (including input from the Cordilleran ice sheet) suggest that the lakes filled every three to seven decades. The hydrostatic prerequisites for a jokulhlaup were thus re-established scores of times during the 2,000- to 2,500-yr episode of last-glacial damming. J Harlen Bretz9s “Spokane flood” outraged geologists six decades ago, partly because it seemed to flaunt catastrophism. The concept that Lake Missoula discharged regularly as jokulhlaups now accords Bretz9s catastrophe with uniformitarian principles.
311 citations
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Performance Metrics
| Year | Papers |
|---|---|
| 2025 | 20 |
| 2024 | 30 |
| 2023 | 57 |
| 2022 | 67 |
| 2021 | 32 |
| 2020 | 29 |