Discussion of “Sea-level changes along the coasts of the United States in recent years”

1949 ◽  
Vol 30 (6) ◽  
pp. 918
Author(s):  
Henry W. Bigelow
Keyword(s):  
United States ◽  
Sea Level ◽  
The United States ◽  
Sea Level Changes

scholarly journals River-discharge effects on United States Atlantic and Gulf coast sea-level changes

2018 ◽  
Vol 115 (30) ◽  
pp. 7729-7734 ◽  
Author(s):  
Christopher G. Piecuch ◽  
Klaus Bittermann ◽  
Andrew C. Kemp ◽  
Rui M. Ponte ◽  
Christopher M. Little ◽  
...  
Keyword(s):  
United States ◽  
Sea Level ◽  
River Discharge ◽  
Sea Level Change ◽  
The United States ◽  
Ocean Dynamics ◽  
Sea Level Changes ◽  
Level Change ◽  
Vertical Land Motion ◽  
Coastal Sea

Identifying physical processes responsible for historical coastal sea-level changes is important for anticipating future impacts. Recent studies sought to understand the drivers of interannual to multidecadal sea-level changes on the United States Atlantic and Gulf coasts. Ocean dynamics, terrestrial water storage, vertical land motion, and melting of land ice were highlighted as important mechanisms of sea-level change along this densely populated coast on these time scales. While known to exert an important control on coastal ocean circulation, variable river discharge has been absent from recent discussions of drivers of sea-level change. We update calculations from the 1970s, comparing annual river-discharge and coastal sea-level data along the Gulf of Maine, Mid-Atlantic Bight, South Atlantic Bight, and Gulf of Mexico during 1910–2017. We show that river-discharge and sea-level changes are significantly correlated (p<0.01), such that sea level rises between 0.01 and 0.08 cm for a 1 km3 annual river-discharge increase, depending on region. We formulate a theory that describes the relation between river-discharge and halosteric sea-level changes (i.e., changes in sea level related to salinity) as a function of river discharge, Earth’s rotation, and density stratification. This theory correctly predicts the order of observed increment sea-level change per unit river-discharge anomaly, suggesting a causal relation. Our results have implications for remote sensing, climate modeling, interpreting Common Era proxy sea-level reconstructions, and projecting coastal flood risk.

scholarly journals HOLOCENE SEA-LEVEL CHANGES ALONG THE UNITED STATES’ ATLANTIC COAST

Oceanography ◽  
2011 ◽  
Vol 24 (2) ◽  
pp. 70-79 ◽  
Author(s):  
Simon Engelhart ◽  
Benjamin Horton ◽  
Andrew Kemp
Keyword(s):  
United States ◽  
Sea Level ◽  
Atlantic Coast ◽  
The United States ◽  
Sea Level Changes ◽  
Holocene Sea Level

scholarly journals Upper-Ocean Contribution to Short-Term Regional Coastal Sea Level Variability along the United States

2017 ◽  
Vol 30 (11) ◽  
pp. 4037-4045 ◽  
Author(s):  
Veronica Nieves ◽  
Marta Marcos ◽  
Josh K. Willis
Keyword(s):  
United States ◽  
Sea Level ◽  
Thermal Structure ◽  
Regional Scale ◽  
Internal Variability ◽  
The United States ◽  
Upper Ocean ◽  
Sea Level Changes ◽  
Short Term ◽  
Sea Level Variability

Abstract The upper ocean thermal structure is largely influenced by natural internal variability, and it modulates global surface temperature as well as regional sea level anomalies over decadal time scales. The internal variability of some important oceanographic processes, such as the Pacific decadal oscillation, can cause differences of 10 to 20 cm relative to the global mean in many coastal locations. These differences are sufficient to alter decisions between soft and/or large protective measures on every coast. Yet, current indicators of sea level changes are based on either surface variables or subsurface ocean measurements through the entire water column. There is also a lack of focus on short-term predictions of sea level change and concrete applications of these predictions at regional scale, which clouds local decision-making. The results herein confirm that the information contained within the top 300 m of the ocean is essential to capture decadal, regional relative sea level variability, whereas depths well below the thermocline do not appear to be closely tied to these large oscillations. Hence, the authors propose a regionally scoped indicator based on upper-ocean temperature as a first step toward identifying trend changes in short-term sea level rise over large coastal regions of the United States. The proposed indicator is a promising new tool that could help close the gaps mentioned above and improve the utility of existing local sea level records.

scholarly journals Alongshore Wind Forcing of Coastal Sea Level as a Function of Frequency

2006 ◽  
Vol 36 (11) ◽  
pp. 2173-2184 ◽  
Author(s):  
Holly F. Ryan ◽  
Marlene A. Noble
Keyword(s):  
United States ◽  
Frequency Response ◽  
Sea Level ◽  
Response Function ◽  
Wind Field ◽  
Frequency Response Function ◽  
The United States ◽  
The West ◽  
Coastal Sea ◽  
Alongshore Wind

Abstract The amplitude of the frequency response function between coastal alongshore wind stress and adjusted sea level anomalies along the west coast of the United States increases linearly as a function of the logarithm (log10) of the period for time scales up to at least 60, and possibly 100, days. The amplitude of the frequency response function increases even more rapidly at longer periods out to at least 5 yr. At the shortest periods, the amplitude of the frequency response function is small because sea level is forced only by the local component of the wind field. The regional wind field, which controls the wind-forced response in sea level for periods between 20 and 100 days, not only has much broader spatial scales than the local wind, but also propagates along the coast in the same direction as continental shelf waves. Hence, it has a stronger coupling to and an increased frequency response for sea level. At periods of a year or more, observed coastal sea level fluctuations are not only forced by the regional winds, but also by joint correlations among the larger-scale climatic patterns associated with El Niño. Therefore, the amplitude of the frequency response function is large, despite the fact that the energy in the coastal wind field is relatively small. These data show that the coastal sea level response to wind stress forcing along the west coast of the United States changes in a consistent and predictable pattern over a very broad range of frequencies with time scales from a few days to several years.

The rise and fall of late Paleozoic trilobites of the United States

1999 ◽  
Vol 73 (2) ◽  
pp. 164-175 ◽  
Author(s):  
David K. Brezinski
Keyword(s):  
United States ◽  
North America ◽  
Sea Level ◽  
Adaptive Radiation ◽  
The United States ◽  
Upper Permian ◽  
Late Paleozoic ◽  
Lower Permian ◽  
Stage 4 ◽  
Stage 1

Based on range data and generic composition, four stages of evolution are recognized for late Paleozoic trilobites of the contiguous United States. Stage 1 occurs in the Lower Mississippian (Kinderhookian-Osagean) and is characterized by a generically diverse association of short-ranging, stenotopic species that are strongly provincial. Stage 2 species are present in the Upper Mississippian and consist of a single, eurytopic, pandemic genus, Paladin. Species of Stage 2 are much longer-ranging than those of Stage 1, and some species may have persisted for as long as 12 m.y. Stage 3 is present within Pennsylvanian and Lower Permian strata and consists initially of the eurytopic, endemic genera Sevillia and Ameura as well as the pandemic genus Ditomopyge. During the middle Pennsylvanian the very long-ranging species Ameura missouriensis and Ditomopyge scitula survived for more than 20 m.y. During the late Pennsylvanian and early Permian, a number of pandemic genera appear to have immigrated into what is now North America. Stage 4 is restricted to the Upper Permian (late Leonardian-Guadalupian) strata and is characterized by short-ranging, stenotopic, provincial genera.The main causal factor controlling the four-stage evolution of late Paleozoic trilobites of the United States is interpreted to be eustacy. Whereas Stage 1 represents an adaptive radiation developed during the Lower Mississippian inundation of North America by the Kaskaskia Sequence, Stage 2 is present in strata deposited during the regression of the Kaskaskia sea. Stage 3 was formed during the transgression and stillstand of the Absaroka Sequence and, although initially endemic, Stage 3 faunas are strongly pandemic in the end when oceanic circulation patterns were at a maximum. A mid-Leonardian sea-level drop caused the extinction of Stage 3 fauna. Sea-level rise near the end of the Leonardian and into the Guadalupian created an adaptive radiation of stentopic species of Stage 4 that quickly became extinct with the latest Permian regression.

scholarly journals El mayor registro de elevación de Mustela frenata (Carnivora: Mustelidae) y distribución en el departamento de Calda, región andina de Colombia

2014 ◽  
Vol 1 (2) ◽  
pp. 7-9
Author(s):  
Sergio Escobar-Lasso ◽  
Margarita Gil-Fernández
Keyword(s):  
United States ◽  
South America ◽  
Sea Level ◽  
The United States ◽  
Western Hemisphere ◽  
Geographical Range ◽  
The North ◽  
Northern South America

The long-tailed weasel Mustela frenata Lichtenstein, 1831 has the greatest geographical range among mustelids in the western hemisphere (Harding & Dragoo 2012). The range of M. frenata extends from the north of the United States, near the Canadian border, to northern South America (Sheffield & Thomas 1997), from sea level to 3800 masl (Sheffield & Thomas 1997, Reid & Helgen 2008).

Ice-sheet surges and the geological record

1969 ◽  
Vol 6 (4) ◽  
pp. 903-910 ◽  
Author(s):  
John T. Hollin
Keyword(s):  
United States ◽  
Sea Level ◽  
Ice Sheet ◽  
The United States ◽  
Tectonic Activity ◽  
Ice Ages ◽  
Antarctic Ice Sheet ◽  
Geological Record ◽  
Glacial Time ◽  
The Antarctic

If they had occurred, ice-sheet surges would have caused sea-level rises of up to 50 m from Gondwanaland and say 20 m from Antarctica. The rises would have taken 100 years or much less, and the sub sequent falls would have taken 50 000 years or so, as the ice built up again. Such rises may explain the extensive (hundreds of miles ?) and sharp (submergence time 4 years ?) coal – marine shale contacts in the Carboniferous cyclothems. The chief rival explanation for these contacts is sudden subsidence. Tests should show (1) if such contacts are better correlated with periods of glaciation or with areas of tectonic activity, (2) how extensive the contacts really are, (3) if there is any evidence of erosion during sea-level falls, (4) if the amplitudes and periods of the cycles fit surges or subsidence, (5) how fast the submergences were, and (6) if any coolings began at the contacts. Wilson suggests that in the Pleistocene the surge coolings were sufficient to trigger the northern ice ages. If so, interglacial pollen profiles should show rapid but temporary marine transgressions beginning at the break of climate. Evidence suggesting such transgressions occurs in England and the United States, but is still insufficient to disprove explanations such as local downwarping. There is no evidence yet for surges in Wisconsin or Post-glacial time. There is some evidence that the Antarctic Ice Sheet is currently building up, but this could be a response to a Post-glacial accumulation increase rather than the prelude to a surge.

A Remarkable Array: Species Diversity in the United States

2000 ◽  
Author(s):  
Bruce A. Stein ◽  
Larry E. Morse
Keyword(s):  
United States ◽  
North America ◽  
Sea Level ◽  
Eastern China ◽  
The United States ◽  
The Other ◽  
Death Valley ◽  
The Arctic ◽  
Blue Ridge Mountains ◽  
Little Tennessee River

The Carolina hemlock (Tsuga caroliniana) survives in just a few rocky streambeds along the lower slopes of the Blue Ridge Mountains. Other species of hemlock abound across the United States, but none bear a close resemblance to this particular tree. The closest relatives of the Carolina hemlock, in fact, survive in only one other forest on Earth, some 7,000 miles away in Hubei province of eastern China. The forests of eastern Asia and eastern North America are so similar that if you were suddenly transported from one to the other, you would be hard-pressed to tell them apart. In the swift mountain streams rushing past these seemingly displaced hemlocks live a number of small, colorful fish known as darters. Darters are found only in North America and have evolved into a prolific variety of fishes. Up to 175 species inhabit U.S. waters, including the famous snail darter (Percina tanasi), which brought endangered species issues to the fore when it held up construction of the Tellico Dam on the Little Tennessee River. How is it that these two organisms, hemlock and darter, one with its closest relatives on the other side of the globe and the other found nowhere else in the world, came to be living side by side? Just how many plants and animals share the piece of Earth that we know as the United States of America? Why these and not others? These are central questions for understanding the diversity of the nation’s living resources. The United States encompasses an enormous piece of geography. With more than 3.5 million square miles of land and 12,000 miles of coastline, it is the fourth largest country on Earth, surpassed only by Russia, Canada, and China. The nation spans nearly a third of the globe, extending more than 120 degrees of longitude from eastern Maine to the tip of the Aleutian chain, and 50 degrees in latitude from Point Barrow above the Arctic Circle to the southern tip of Hawaii below the tropic of Cancer. This expanse of terrain includes an exceptional variety of topographic features, from Death Valley at 282 feet below sea level to Mt. McKinley at 20,320 feet above sea level.

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