Three forgotten earthquakes

1963 ◽  
Vol 53 (3) ◽  
pp. 687-692
Author(s):  
Gerald R. MacCarthy
Keyword(s):  
United States ◽  
New York ◽  
North Carolina ◽  
South Carolina ◽  
Coastal Plain ◽  
Maximum Intensity ◽  
Atlantic Coastal Plain ◽  
Eastern United States ◽  
Atlantic Coastal

Abstract For a given maximum intensity, most earthquakes of the Eastern United States are felt over much wider area than their western counterparts. Several of these eastern shocks, have, because of their relatively low maximum intensities, received little or no attention in seismological literature. Three such earthquakes will be described in terms of contemporary accounts: those of March 9, 1828, April 29, 1852, and of August 31, 1861. In no case did the maximum intensity exceed about VI on the Mercalli Scale, yet each was felt over many thousands of square miles. The 1828 shock affected at least 190,000 square miles, and was reported from Pennsylvania to South Carolina. That of 1852 affected about 187,000 square miles, and was reported from New York to North Carolina. That of 1861 affected at least 280,000 square miles, and was reported from Maryland to the Georgia-Alabama border. All three were felt from the Atlantic Coastal Plain westward into Ohio.

Biostratigraphic Correlation of Pleistocene Marine Deposits and Sea Levels, Atlantic Coastal Plain of the Southeastern United States

1980 ◽  
Vol 13 (2) ◽  
pp. 213-229 ◽  
Author(s):  
Thomas M. Cronin
Keyword(s):  
North Carolina ◽  
South Carolina ◽  
Sea Level ◽  
Late Pleistocene ◽  
Coastal Plain ◽  
Atlantic Coastal Plain ◽  
Early Pleistocene ◽  
Middle Pleistocene ◽  
Sea Levels ◽  
Atlantic Coastal

AbstractMarine ostracodes from 50 localities were studied to determine the age and elevation of Pleistocene sea levels in the Atlantic coastal plain from Maryland to northern Florida. Using ostracode taxon and concurrent ranges, published planktic biostratigraphic, paleomagnetic, and radiometric data, ostracode assemblage zones representing early (1.8-1.0 my), middle (0.7-0.4 my), and late (0.3-0.01 my) Pleistocene deposition were recognized and used as a basis for correlation. Ostracode biofacies signifying lagoonal, oyster bank, estuarine, open sound, and inner sublittoral environments provided estimated ranges of paleodepths for each locality. From these data the following minimum and maximum Pleistocene sea-level estimates were determined for the southeastern coastal plain: late Pleistocene, 2–10 m from Maryland to northern Florida; middle Pleistocene, 6–15 m in northern South Carolina; early Pleistocene, 4–22 m in central North Carolina, 13–35 m in southern North Carolina, and 6–27 m in South Carolina. Climatically induced glacio-eustatic sea-level fluctuations adequately account for the late Pleistocene sea-level data, but other factors, possibly differential crustal uplift, may have complicated the early Pleistocene record.

scholarly journals Fate of the other redcoat: remnants of colonial British foxes in the eastern United States

2015 ◽  
Vol 97 (1) ◽  
pp. 298-309 ◽  
Author(s):  
Adrienne E. Kasprowicz ◽  
Mark J. Statham ◽  
Benjamin N. Sacks
Keyword(s):  
United States ◽  
Coastal Plain ◽  
Red Fox ◽  
Hudson River ◽  
Atlantic Coastal Plain ◽  
Population Increase ◽  
Eastern United States ◽  
Red Foxes ◽  
Atlantic Coastal ◽  
Natural Population Increase

Abstract Red foxes were absent or rare in the southeastern United States until the late 1800s. Their origins potentially include natural population increase/expansion, translocations from Europe, and, eventually, 20th century fur farming. Previous studies have found no European haplotypes in North America, but few samples were sourced from the Atlantic coastal plain, closer to the source of putative introductions. Through analysis of mitochondrial DNA in 584 red foxes from this region, we identified indigenous haplotypes in ≥ 35% of foxes, 1 of 2 European haplotypes in 17% of foxes and fur farm haplotypes in ≥ 13% of foxes; another 35% of foxes had haplotypes potentially indigenous or native. In contrast, only 3 of 135 (2%) male foxes carried a single European Y chromosome haplotype. Most European and fur farm haplotypes were found near the densely human-populated coastal plain and Hudson River lowlands; most red foxes of the Appalachians and Piedmont had native eastern haplotypes. Our findings suggest that the more remote, upland populations primarily reflect indigenous red fox matrilines, whereas urban-associated populations in and around the mid-Atlantic coastal plain and Hudson lowlands reflect an admixture of native and nonnative maternal sources. Autosomal markers are needed to further elucidate the extent of European and fur farm introgression in the Appalachians and further west.

Characterizing Fundamental Resonance Peaks on Flat-Lying Sediments Using Multiple Spectral Ratio Methods: An Example from the Atlantic Coastal Plain, Eastern United States

2021 ◽  
Author(s):  
Lisa S. Schleicher ◽  
Thomas L. Pratt
Keyword(s):  
United States ◽  
Coastal Plain ◽  
Site Response ◽  
Spectral Ratio ◽  
Atlantic Coastal Plain ◽  
Unconsolidated Sediments ◽  
Eastern United States ◽  
Fundamental Resonance ◽  
Hvsr Method ◽  
Atlantic Coastal

ABSTRACT Damaging ground motions from the 2011 Mw 5.8 Virginia earthquake were likely increased due to site amplification from the unconsolidated sediments of the Atlantic Coastal Plain (ACP), highlighting the need to understand site response on these widespread strata along the coastal regions of the eastern United States. The horizontal-to-vertical spectral ratio (HVSR) method, using either earthquake signals or ambient noise as input, offers an appealing method for measuring site response on laterally extensive sediments, because it requires a single seismometer rather than requiring a nearby bedrock site to compute a horizontal sediment-to-bedrock spectral ratio (SBSR). Although previous studies show mixed results when comparing the two methods, the majority of these studies investigated site responses in confined sedimentary basins that can generate substantial 3D effects or have relatively small reflection coefficients at their base. In contrast, the flat-lying ACP strata and the underlying bedrock reflector should cause 1D resonance effects to dominate site response, with amplification of the fundamental resonance peaks controlled by the strong impedance contrast between the base of the sediments and the underlying bedrock. We compare site-response estimates on the ACP strata derived using the HVSR and SBSR methods from teleseismic signals recorded by regional arrays and observe a close match in the frequencies of the fundamental resonance peak (f0) determined by both methods. We find that correcting the HVSR amplitude using source term information from a bedrock site and multiplying the peak by a factor of 1.2 results in amplitude peaks that, on average, match SBSR results within a factor of 2. We therefore conclude that the HVSR method may successfully estimate regional linear weak-motion site-response amplifications from the ACP, or similar geologic environments, when appropriate region-specific corrections to the amplitude ratios are used.

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