A Sault-outlet-referenced mid- to late-Holocene paleohydrograph for Lake Superior constructed from strandplains of beach ridges

2012 ◽  
Vol 49 (11) ◽  
pp. 1263-1279 ◽  
Author(s):  
John W. Johnston ◽  
Erin P. Argyilan ◽  
Todd A. Thompson ◽  
Steve J. Baedke ◽  
Kenneth Lepper ◽  
...  
Keyword(s):  
Water Level ◽  
Linear Trend ◽  
Lake Superior ◽  
Optically Stimulated Luminescence ◽  
Glacial Isostatic Adjustment ◽  
Beach Ridges ◽  
The Past ◽  
Isostatic Adjustment ◽  
History Of ◽  
Past Millennium

The most detailed Lake Superior paleohydrograph relative to the current outlet near Sault Ste. Marie, Ontario–Michigan, was constructed from four strandplains of beach ridges. This provides a history of water-level, glacial isostatic adjustment (GIA), and the active outlet prior to monitoring and regulation. Four relative paleohydrographs that are offset and subparallel owing to differences in GIA were produced from 321 basal foreshore elevations and 56 optically stimulated luminescence ages. Subtracting modeled elevations in defined millennial lake phases between relative paleohydrographs and similarity between an inferred Sault Ste. Marie (hereinafter, Sault) paleohydrograph and data near the zero isobase corroborates rates of GIA derived from water-level gauges. A change in trend in the Sault paleohydrograph is related to the final separation of Lake Superior from Lakes Michigan and Huron and is the youngest age reported at 1060 ± 100 years. A near-horizontal trend in the Sault paleohydrograph for the past millennium has an intercept that is close to the historical average for Lake Superior. A consistently linear trend from about 2 to 1 ka suggests a relatively stable outlet similar to the past millennium, but a decreasing trend from 3 to 1 ka suggests an outlet other than the Sault. Although intercept data beyond the last millennium are similar in elevation to the reported bedrock sill near Chicago (Hansel et al. 1985), we argue that the Port–Huron outlet was the active outlet during this time and the inferred paleohydrograph of Baedke and Thompson (2000) requires reevaluation.

scholarly journals Evolution of word meanings through metaphorical mapping: Systematicity over the past millennium.

2018 ◽  
Author(s):  
Yang Xu ◽  
Barbara Claire Malt ◽  
Mahesh Srinivasan
Keyword(s):  
Large Scale ◽  
Computational Models ◽  
Compact Set ◽  
Large Set ◽  
Word Meanings ◽  
The Past ◽  
History Of ◽  
Cognitive Principles ◽  
Metaphorical Mapping ◽  
Past Millennium

One way that languages are able to communicate a potentially infinite set of ideas through a finite lexicon is by compressing emerging meanings into words, such that over time, individual words come to express multiple, related senses of meaning. We propose that overarching communicative and cognitive pressures have created systematic directionality in how new metaphorical senses have developed from existing word senses over the history of English. Given a large set of pairs of semantic domains, we used computational models to test which domains have been more commonly the starting points (source domains) and which the ending points (target domains) of metaphorical mappings over the past millennium. We found that a compact set of variables, including externality, embodiment, and valence, explain directionality in the majority of about 5000 metaphorical mappings recorded over the past 1100 years. These results provide the first large-scale historical evidence that metaphorical mapping is systematic, and driven by measurable communicative and cognitive principles.

A 5700-year-old beach-ridge set at Cape Canaveral, Florida, and its implication for Holocene sea-level history in the southeastern USA

The Holocene ◽  
2021 ◽  
pp. 095968362110499
Author(s):  
Kathleen Rodrigues ◽  
Frank W Stapor ◽  
William J Rink ◽  
James S Dunbar ◽  
Glen Doran
Keyword(s):  
Sea Level ◽  
Atlantic Coast ◽  
High Water ◽  
South Florida ◽  
Beach Ridge ◽  
Beach Ridges ◽  
The Past ◽  
History Of ◽  
Depositional Age ◽  
Holocene Sea Level

The Cape Canaveral Peninsula is the largest Holocene coastal sand deposit composed of beach ridges on the Atlantic coast of Florida. It is composed of 16 beach-ridge sets that are separated by erosional surfaces. Despite its prominence as a Holocene coastal depocenter, there are a limited amount of chronological data constraining the timing of its formation. In this study, we apply optically stimulated luminescence (OSL) dating on sand-sized quartz and radiocarbon dating on individual marine shells to develop a refined chronology of the Cape Canaveral beach-ridge plain with particular focus on constraining the depositional age of the northwesterly-most, and geographically oldest, beach-ridge set on the peninsula. We obtain an average OSL age of 5680 ± 240 years ( n = 4) for the initiation of coastal deposition at Cape Canaveral. The new ages, and the organization of beach ridges into 16 distinct sets indicates that the Cape Canaveral beach-ridge plain experienced an ~5700-year history of alternating deposition and erosion, with 75% of present-day Cape Canaveral (Beach-ridge Sets 5–16) deposited over the past 2000 years and Beach-ridge Sets 8–16 comprising 50% of the area over the past 1000 years. Because the minimum swale elevations of the ~5700-year Beach-ridge Set 1, and those of all the younger beach-ridge sets, are within several decimeters of present-day mean higher high water, we hypothesize that all the beach ridges present at Cape Canaveral could have been deposited at or within decimeters of present-day sea level. There is no evidence for Holocene “highstand” events over the past 5700 years in the published sea level curves from northeast and south Florida, which are based on subsurface estuarine foraminifera/leaf litter and mangrove peat data, respectively. This dichotomy illustrates the need to integrate both subaerial and subsurface data to produce a more realistic Holocene sea-level curve for the southeastern United States.

Can moisture content estimates from nuclear magnetic resonance improve optically stimulated luminescence dating - first results on Loess samples from Toshan/Iran

2020 ◽  
Author(s):  
Raphael Dlugosch ◽  
Christian Zeeden ◽  
Tobias Lauer ◽  
Sumiko Tsukamoto
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Moisture Content ◽  
Dose Rate ◽  
Optically Stimulated Luminescence ◽  
Luminescence Dating ◽  
The Past ◽  
History Of ◽  
Wilting Point ◽  
Nuclear Magnetic

<p>Dating of loess deposits using optically stimulated luminescence (OSL) enable us to extract important information about the climate during the last ~150 ka. A good estimation of the dose rate during the past is essential for OSL and depends, among others, on the history of the moisture content in the proximity of the dated sample. While the current moisture content can be measured by heating/drying, the history of the moisture variations of a sample is generally unknown. Reference values reported on similar materials and climate conditions may provide a range for the expected moisture variations in the past, but these values are generally rough guesses and not depth- and time-specific.</p><p>Nuclear magnetic resonance (NMR) relaxometry targeting the hydrogens of the pore fluid can estimate the current moisture content of a sample without heating. Additionally, the NMR relaxation time distribution yields information of the expected moisture content for a given field potential (e.g. wilting point). This can help to estimate a sample-specific range of likely moisture variation in a quick (several min) and no-invasive way.</p><p>We discuss this new approach on a loess profile from Toshan (Iran) published previously by (Lauer et al., 2017) and (Vlaminck, 2018). The later pointed out inconsistencies in the obtained age model. The estimated sample specific moisture content for the wilting point (15 to 35 wt.%) provide the low boundary for the moisture content estimate, which is higher than previously assumed (5 wt.%). The new dose rate calculated for these sample specific moisture content values lead to clearly older and more consistent ages (less age inversions).</p><p>We suggest that NMR derived moisture content data is valuable for obtaining information on the moisture content of samples. Especially the minimum moisture can be derived reliably, giving more robust water content estimates for OSL dating.</p><p><strong> </strong></p><p><strong> </strong></p><p><strong>References</strong></p><p>Lauer, T., Vlaminck, S., Frechen, M., Rolf, C., Kehl, M., Sharifi, J., Lehndorff, E., Khormali, F., 2017. The Agh Band loess-palaeosol sequence – A terrestrial archive for climatic shifts during the last and penultimate glacial–interglacial cycles in a semiarid region in northern Iran. Quaternary International, Loess, soils and climate change in Iran and vicinity 429, 13–30. https://doi.org/10.1016/j.quaint.2016.01.062</p><p>Vlaminck, S., 2018. Northeastern Iranian loess and its palaeoclimatic implications (PhD Thesis). Universität zu Köln.</p>

scholarly journals Modeling the epidemiological history of plague in Central Asia: Palaeoclimatic forcing on a disease system over the past millennium

BMC Biology ◽  
2010 ◽  
Vol 8 (1) ◽  
pp. 112 ◽  
Author(s):  
Kyrre Linne Kausrud ◽  
Mike Begon ◽  
Tamara Ben Ari ◽  
Hildegunn Viljugrein ◽  
Jan Esper ◽  
...  
Keyword(s):  
Central Asia ◽  
The Past ◽  
History Of ◽  
Past Millennium

scholarly journals Late Holocene (0–6 ka) sea-level changes in the Makassar Strait, Indonesia

2020 ◽  
Vol 16 (4) ◽  
pp. 1187-1205 ◽  
Author(s):  
Maren Bender ◽  
Thomas Mann ◽  
Paolo Stocchi ◽  
Dominik Kneer ◽  
Tilo Schöne ◽  
...  
Keyword(s):  
Sea Level ◽  
Late Holocene ◽  
Glacial Isostatic Adjustment ◽  
Mantle Structure ◽  
Ice Melting ◽  
Sea Level Changes ◽  
Relative Sea Level ◽  
The Past ◽  
Isostatic Adjustment ◽  
Spermonde Archipelago

Abstract. The Spermonde Archipelago, off the coast of southwest Sulawesi, consists of more than 100 small islands and hundreds of shallow-water reef areas. Most of the islands are bordered by coral reefs that grew in the past in response to paleo relative sea-level changes. Remnants of these reefs are preserved today in the form of fossil microatolls. In this study, we report the elevation, age, and paleo relative sea-level estimates derived from fossil microatolls surveyed in five islands of the Spermonde Archipelago. We describe 24 new sea-level index points, and we compare our dataset with both previously published proxies and with relative sea-level predictions from a set of 54 glacial isostatic adjustment (GIA) models, using different assumptions on both ice melting histories and mantle structure and viscosity. We use our new data and models to discuss Late Holocene (0–6 ka) relative sea-level changes in our study area and their implications in terms of modern relative sea-level estimates in the broader South and Southeast Asia region.

Great States

2016 ◽  
Vol 75 (4) ◽  
pp. 957-972 ◽  
Author(s):  
Timothy Brook
Keyword(s):  
East Asia ◽  
Global History ◽  
Virtual Absence ◽  
The Past ◽  
Distinctive Type ◽  
History Of ◽  
History Of Empire ◽  
Past Millennium

“Great State” has gone missing from the vocabulary of state formations in Asia. Though widely used across Inner and East Asia over the past millennium, the term means nothing to most scholars today. It is not flagged, rarely noted, and never theorized. Recent thinking about inter-polity relations in Inner and East Asia has led me to regard the Great State as a distinctive type of political formation that should have a place in our conceptual toolkit if we scholars of Asia are to participate in writing the global history of empire. Given its near ubiquity, the virtual absence of a discourse on the Great State, ancient or modern, Asian or otherwise, may be more than just a curiosity, and it is worth wondering why.

scholarly journals Sea-level stands from the Western Mediterranean over the past 6.5 million years

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Oana A. Dumitru ◽  
Jacqueline Austermann ◽  
Victor J. Polyak ◽  
Joan J. Fornós ◽  
Yemane Asmerom ◽  
...  
Keyword(s):  
Sea Level ◽  
Western Mediterranean ◽  
Glacial Isostatic Adjustment ◽  
Mean Sea Level ◽  
The Past ◽  
Isostatic Adjustment ◽  
Future Warming ◽  
Global Mean Sea Level ◽  
Global Mean

AbstractSea-level reconstructions are important for understanding past ice sheet variability and its response to past and future warming. Here we present Neogene and Quaternary sea-level snapshots using phreatic overgrowths on speleothems (POS) from caves on Mallorca, Spain. POS are excellent sea level index points because of their clear relationship to sea level and precise U–Pb chronology. We find that local sea-level before and at the onset of the Messinian Salinity Crisis was at 33.3 ± 0.25 m (6.54 ± 0.37 Ma) and 31.8 ± 0.25 m (5.86 ± 0.60 Ma) above present levels, respectively. We further present global mean sea level (GMSL) estimates, i.e. local sea level corrected for glacial isostatic adjustment and long-term uplift, for three other POS. The results show that GMSL during the Pliocene–Pleistocene Transition was 6.4 m (− 2.0–8.8 m) at 2.63 ± 0.11 Ma and during the beginning and the end of the Mid-Pleistocene Transition was − 1.1 m (− 5.6–2.4 m) and 5 m (1.5–8.1 m), respectively. These estimates provide important constraints for the past evolution of sea level and show that local sea level prior to the MSC was similar to the highest stand during the Pliocene, with markedly lower position afterwards.

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