Publications
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Observatories, program in USA
The Geomagnetism Program of the US Geological Survey has, for over a century now, monitored the Earth's magnetic field through a network of magnetic observatories and conducted scientific analysis on the data collected. The program traces its origins to the Reorganization Act of 1843, in which Congress authorized the creation of a coastal survey agency, as part of the Treasury Department, that was
Authors
Jeffrey J. Love, J.B. Townshend
Magnetic indices
Magnetic indices are simple measures of magnetic activity that occurs, typically, over periods of time of less than a few hours and which is recorded by magnetometers at ground‐based observatories (Mayaud, 1980; Rangarajan, 1989; McPherron, 1995). The variations that indices measure have their origin in the Earth's ionosphere and magnetosphere. Some indices having been designed specifically to qua
Authors
Jeffrey J. Love, K.J. Remick
Coupling alongshore variations in wave energy to beach morphologic change using the SWAN wave model at Ocean Beach, San Francisco, CA
Coastal managers have faced increasing pressure to manage their resources wisely over the last century as a result of heightened development and changing environmental forcing. It is crucial to understand seasonal changes in beach volume and shape in order to identify areas vulnerable to accelerated erosion. Shepard (1950) was among the first to quantify seasonal beach cycles. Sonu and Van Beek (1
Authors
Jodi L. Eshleman, Patrick L. Barnard, Li H. Erikson, Daniel M. Hanes
Model scenarios of shoreline change at Kaanapali Beach, Maui, Hawaii: Seasonal and extreme events
Kaanapali beach is a well-defined littoral cell of carbonate sand extending 2 km south from Black Rock (a basalt headland) to Hanakao'o Point. The beach experiences dynamic seasonal shoreline change forced by longshore transport from two dominant swell regimes. In summer, south swells (Hs = 1–2 m Tp = 14–25 s) drive sand to the north, while in winter, north swells (Hs = 5–8 m Tp = 14–20 s) drive s
Authors
Sean Vitousek, Charles H. Fletcher, Mark A. Merrifield, Geno Pawlak, Curt D. Storlazzi
Pliocene environments
The Pliocene spans the interval of Earth history from ca. 5.3 to 1.8 million years ago (Ma). Although details are still debated there is much evidence from continental and oceanic locations indicating that conditions from 5.3 to about 3.0 Ma were often warmer than in modern times in mid- and high latitudes and that climate variability was subdued compared to the Pleistocene. Millennial-scale early
Authors
R. Z. Poore
Swash zone characteristics at Ocean Beach, San Francisco, CA
Runup data collected during the summer of 2005 at Ocean Beach, San Francisco, CA are analyzed and considered to be typical summer swash characteristics at this site. Analysis shows that the beach was dissipative with Iribarren numbers between 0.05 and 0.4 and that infragravity energy dominated. Foreshore slopes were mild between 0.01 and 0.05 with swash periods on the order of a minute. Predicted
Authors
L. H. Erikson, D.M. Hanes, P.L. Barnard, A. E. Gibbs
Glacial landforms on German Bank, Scotian Shelf: evidence for Late Wisconsinan ice-sheet dynamics and implications for the formation of De Geer moraines
The extent and behaviour of the southeast margin of the Laurentide Ice Sheet in Atlantic Canada is of significance in the study of Late Wisconsinan ice sheet-ocean interactions. Multibeam sonar imagery of subglacial, ice-marginal and glaciomarine landforms on German Bank, Scotian Shelf, provides evidence of the pattern of glacial-dynamic events in the eastern Gulf of Maine. Northwest-southeast tre
Authors
Brian J. Todd, Page C. Valentine, Oddvar Longva, John Shaw
Spatially continuous interpolation of water stage and water depths using the Everglades depth estimation network (EDEN)
The Everglades Depth Estimation Network (EDEN) is an integrated network of real-time water-level monitoring, ground-elevation modeling, and water-surface modeling that provides scientists and managers with current (2000-present), online water-stage and water-depth information for the entire freshwater portion of the Greater Everglades. Continuous daily spatial interpolations of the EDEN network st
Authors
Leonard Pearlstine, Aaron Higer, Monica Palaseanu, Ikuko Fujisaki, Frank Mazzotti
Comparison of flood lavas on Earth and Mars
Flood lavas, by definition, cover vast areas in great sheets of lava, without the construction of major edifices (e.g., Geikie, 1880; Washington, 1922; Tyrrell, 1937; Self et al., 1997). The flat terrain that flood lavas produce has led to the term “plateau volcanism” to be used as a synonym for flood volcanism. In addition, the classic erosion pattern of flood lavas leaves a series of topographic
Authors
Laszlo P. Keszthelyi, Alfred S. McEwen
Tampa Bay as a model estuary for examining the impact of human activities on biogeochemical processes: an introduction
Tampa Bay is a shallow, Y-shaped coastal embayment that is located along the center of the Florida Platform – an expansive accumulation of Cretaceous–Tertiary shallow-water carbonates and evaporites that were periodically exposed during glacio–eustatic sea level fluctuations. As a consequence, extensive karstification likely had a controlling impact on the geologic evolution of Tampa Bay. Despite
Authors
Peter W. Swarzenski, Mark Baskaran, Carl S. Henderson, Kim Yates