Reconstruction of Prehistoric Landfall Frequencies of Catastrophic Hurricanes in Northwestern Florida from Lake Sediment Records

2000 ◽  
Vol 54 (2) ◽  
pp. 238-245 ◽  
Author(s):  
Kam-biu Liu ◽  
Miriam L. Fearn

Sediment cores from Western Lake provide a 7000-yr record of coastal environmental changes and catastrophic hurricane landfalls along the Gulf Coast of the Florida Panhandle. Using Hurricane Opal as a modern analog, we infer that overwash sand layers occurring near the center of the lake were caused by catastrophic hurricanes of category 4 or 5 intensity. Few catastrophic hurricanes struck the Western Lake area during two quiescent periods 3400–5000 and 0–1000 14C yr B.P. The landfall probabilities increased dramatically to ca. 0.5% per yr during an “hyperactive” period from 1000–3400 14C yr B.P., especially in the first millennium A.D. The millennial-scale variability in catastrophic hurricane landfalls along the Gulf Coast is probably controlled by shifts in the position of the jet stream and the Bermuda High.

Baltica ◽  
2015 ◽  
Vol 28 (2) ◽  
pp. 163-178 ◽  
Author(s):  
Meilutė Kabailienė ◽  
Giedrė Vaikutienė ◽  
Lina Macijauskaitė ◽  
Eugenija Rudnickaitė ◽  
Rimantė Guobytė ◽  
...  

Pollen, plant macrofossil and carbonate analyses supplemented with 14C dating were applied for Lopaičiai hollow and Pakastuva Lake sediment sequences. The new data obtained from two sediment cores were used to reconstruct vegetation cover and environmental changes during Lateglacial and Holocene in Samogitian Upland (NW Lithuania). Different burial conditions of dead ice blocks caused different time of lake sediment start in studied sites. The depositional and vegetation cover history is traced starting at pre-Allerød time in sediment sequence from Lopaičiai core. However, sediment sequence from Pakastuva core provides paleoenvironmental information starting only from the very beginning of Holocene. The study results bring more light on environmental development during Lateglacial and Holocene of specific ice marginal area, which is interlobate insular upland.


2016 ◽  
Vol 13 (3) ◽  
pp. 517 ◽  
Author(s):  
Stephen A. Norton ◽  
George L. Jacobson ◽  
Jiří Kopáček ◽  
Tomáš Navrátil

Environmental contextLead and mercury are toxic atmospheric pollutants emitted in large quantities since 1850. Accumulating lake and peat sediments capture the pollutants from the atmosphere and indirectly record changes in deposition through time. This study of four long-term sediment records addresses the questions, ‘What proportion of this atmospheric deposition is natural background?’ and ‘Does the archive faithfully represent true rates of atmospheric deposition?’ AbstractAtmospheric phenomena have a large influence on the flux of mercury (Hg) and lead (Pb) to terrestrial and aquatic ecosystems. Some direct phenomena involve high-frequency variations in air movement; other indirect processes involve longer-term changes in climate and associated vegetation and hydrology. Here, we use evidence from sediment cores to explore how these atmospheric and landscape processes produced large natural variations in Hg and Pb deposition over thousands of years before industrial pollution. Cores from Sargent Mountain Pond, coastal Maine, USA (16600 years), Plešné Lake, south-western Czech Republic (15000 years), Lake Tulane, central Florida, USA (45000 years), and Caribou Bog, Orono, Maine, USA (10000 years) each illustrate how long-term local environmental changes influence the deposition and net retention of Hg and Pb. Important natural factors that emerge from comparisons among these four sites include forestation, changing groundwater hydrology, evolution of the watershed and lake system and (watershed area)/(lake area) ratio, all overlain by late-Holocene anthropogenic atmospheric pollution.


2021 ◽  
Author(s):  
Nikolina Ilijanić ◽  
Slobodan Miko ◽  
Ozren Hasan ◽  
Dea Brunović ◽  
Martina Šparica Miko ◽  
...  

<p>Lake Visovac is a tufa barrier lake on the Krka River between Roški slap (60 m asl) and Skradinski buk (46 m absl) waterfalls, included in the Krka national park as primarily unaltered area of exceptional natural value. Paleolimnological research was conceived to address a lake evolution and depositional environments through the geophysical survey and collection of the lake sediment cores. A high-resolution bathymetric map was obtained using a multibeam sonar. The average lake depth varies between 20 and 25 m. Sediment cores were investigated to extract physical properties, sedimentological, mineralogical, geochemical and paleoecological records constrained by the radiocarbon chronology, to understand what was happening to both the landscapes and lakescapes of Lake Visovac during the last 2.000 cal yr.</p><p>Significant findings of the project are geomorphological features on the lake bottom: submerged sinkholes of various sizes (up to 40 m deep); submerged tufa barriers in the area of Kalički kuk (southern part of Lake Visovac) at the depths of 15 and 17 m, followed by a series of buried cascade tufa barriers at the depth of 25 m covered with up to 10 m of Holocene lake sediments; submerged vertical tufa barrier up to 32 m-high near the mouth of Čikola River; submerged landslides, small (river) fan structures characterized by sediment waves. Ground-penetrating-radar (GPR) data have been acquired due to the presence of gas-saturated sediments over a large area of the lake, that limited the use of high-resolution acoustic profiling. A total thickness of sediments is up to 40 m. High resolution paleoenvironmental record through the Late Holocene gives evidence of high sedimentation rates in Lake Visovac, variable soil erosion impact on lake sediment composition and carbonate authigenic sedimentation. Higher organic carbon is observed in the last 50 years due to changes in land cover and reforestation. Pleistocene lake sediment outcrops occur up to 20 m above the present lake levels indicating higher lake levels as a consequence of higher elevation of tuffa barriers. Kalički kuk, which lies up to 20 m above present lake level, is a remnant of these barriers which have been dated to MIS5. Results allow us to interpret the environmental and evolutionary dynamics of Lake Visovac in the following way: lake level more than 20 m higher than today in mid-Pleistocene with significantly larger lake volume in Lake Visovac, with active Kalički kuk and Skradinski buk waterfalls; lower lake-level at the beginning of the Holocene when several small lakes existed in isolated basins in the area of Lake Visovac. The tufa barrier at Skradinski buk started to grow faster than the Kalički kuk barriers and waterfalls resulting in their flooding and submergence during the Holocene. The tufa barrier at Skradinski buk has grown 15 m since then. This study demonstrates the role of geomorphological lakebed characteristics in reshaping our understanding of the environmental changes and the future of Lake Visovac.</p><p>The research was conducted as part of the project funded by the Krka National Park and CSF funded QMAD project (IP-04-2019-8505).</p>


2008 ◽  
Vol 43 (2-3) ◽  
pp. 85-98 ◽  
Author(s):  
Joshua R. Thienpont ◽  
Brian K. Ginn ◽  
Brian F. Cumming ◽  
John P. Smol

Abstract Paleolimnological approaches using sedimentary diatom assemblages were used to assess water quality changes over the last approximately 200 years in three lakes from King's County, Nova Scotia. In particular, the role of recent shoreline development in accelerating eutrophication in these systems was assessed. Sediment cores collected from each lake were analyzed for their diatom assemblages at approximately 5-year intervals, as determined by 210Pb dating. Analyses showed that each system has changed, but tracked different ecosystem changes. Tupper and George lakes recorded shifts, which are likely primarily related to climatic warming, with diatom assemblages changing from a preindustrial dominance by Aulacoseira spp. to present-day dominance by Cyclotella stelligera. In addition to the recent climatic-related changes, further diatom changes in the Tupper Lake core between approximately 1820 and 1970 were coincident with watershed disturbances (farming, forestry, and construction of hydroelectric power infrastructure). Black River Lake has recorded an increase in diatom-inferred total phosphorus since about 1950, likely due to impoundment of the Black River system for hydroelectric generation and subsequent changes in land runoff. Before-and-after (i.e., top-bottom) sediment analyses of six other lakes from King's County provided further evidence that the region is being influenced by climatic change (decreases in Aulacoseira spp., increases in planktonic diatom taxa), as well as showing other environmental stressors (e.g., acidification). However, we recorded no marked increase in diatom-inferred nutrient levels coincident with shoreline cottage development in any of the nine study lakes. Paleolimnological studies such as these allow lake managers to place the current limnological conditions into a long-term context, and thereby provide important background data for effective lake management.


2019 ◽  
Vol 30 (2) ◽  
pp. 275-293 ◽  
Author(s):  
Joshua M. Goodwin ◽  
Kenneth E. Sassaman ◽  
Meggan E. Blessing ◽  
David W. Steadman

Prevalent as bird imagery is in the ritual traditions of eastern North America, the bony remains of birds are relatively sparse in archaeological deposits and when present are typically viewed as subsistence remains. A first-millennium ad civic-ceremonial centre on the northern Gulf Coast of Florida contains large pits with bird bones amid abundant fish bone and other taxa. The avian remains are dominated by elements of juvenile white ibises, birds that were taken from offshore rookeries at the time of summer solstices. The pits into which they were deposited were emplaced on a relict dune with solstice orientations. The timing and siting of solstice feasts at this particular centre invites discussion of world-renewal rituality and the significance of birds in not only the timing of these events but also possibly as agents of balance and rejuvenation.


The Holocene ◽  
2020 ◽  
pp. 095968362098168
Author(s):  
Christian Stolz ◽  
Magdalena Suchora ◽  
Irena A Pidek ◽  
Alexander Fülling

The specific aim of the study was to investigate how four adjacent geomorphological systems – a lake, a dune field, a small alluvial fan and a slope system – responded to the same impacts. Lake Tresssee is a shallow lake in the North of Germany (Schleswig-Holstein). During the Holocene, the lake’s water surface declined drastically, predominately as a consequence of human impact. The adjacent inland dune field shows several traces of former sand drift events. Using 30 new radiocarbon ages and the results of 16 OSL samples, this study aims to create a new timeline tracing the interaction between lake and dunes, as well, as how both the lake and the dunes reacted to environmental changes. The water level of the lake is presumed to have peaked during the period before the Younger Dryas (YD; start at 10.73 ka BC). After the Boreal period (OSL age 8050 ± 690 BC) the level must have undergone fluctuations triggered by climatic events and the first human influences. The last demonstrable high water level was during the Late Bronze Age (1003–844 cal. BC). The first to the 9th century AD saw slightly shrinking water levels, and more significant ones thereafter. In the 19th century, the lake area was artificially reduced to a minimum by the human population. In the dunes, a total of seven different phases of sand drift were demonstrated for the last 13,000 years. It is one of the most precisely dated inland-dune chronologies of Central Europe. The small alluvial fan took shape mainly between the 13th and 17th centuries AD. After 1700 cal. BC (Middle Bronze Age), and again during the sixth and seventh centuries AD, we find enhanced slope activity with the formation of Holocene colluvia.


1998 ◽  
Vol 27 ◽  
pp. 275-280 ◽  
Author(s):  
Akira Nishimura ◽  
Toru Nakasone ◽  
Chikara Hiramatsu ◽  
Manabu Tanahashi

Based on sedimenlological and micropaleontological work on three sediment cores collected at about 167° Ε in the western Ross Sea, Antarctica, and accelerator mass spectrometer l4C ages of organic carbon, we have reconstructed environmental changes in the area during the late Quaternary. Since 38 ka BP at latest, this area was a marine environment with low productivity. A grounded ice sheet advanced and loaded the sediments before about 30-25 ka BP. After 25 ka BP, the southernmost site (76°46'S) was covered by floating ice (shelf ice), preventing deposition of coarse terrigenous materials and maintaining a supply of diatom tests and organic carbon until 20 ka BP. The northernmost site (74°33'S) was in a marine environment with a moderate productivity influenced by shelf ice/ice sheet after about 20 ka BP. Since about 10 ka BP, a sedimentary environment similar to the present-day one has prevailed over this area.


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