Characteristics Of Sea Level Records
Climate-related variations of sea level, although small compared to some other geophysical phenomena, share a common property in their spectrum, that is, in the way their power is correlated with frequency. In many geophysical data series large changes are associated with long periods. A few common examples are that small earthquakes are more frequent than large ones, great storms occur less often than small ones, and large meteorites hit the earth less frequently than small ones. Temporally,...
The Modern Global Theory Of The Glacial Isostatic Adjustment Process
The theory of the GIA process is embodied in an integral sea level equation, the solution of which describes the time-dependent separation between the surface of the solid earth and the gravitational equipotential surface that determines the equilibrium level of the sea. This equipotential surface is, of course, precisely the geoid of classical geodesy. The basic ingredients and initial form of this sea level equation SLE were developed in Peltier 1974, 1976 , Peltier and Andrews 1976 , and...
Water Released by Oxidation of Fossil Fuels and Vegetation
The combustion of fossils fuels and burning of tropical forests release water into the atmosphere together with carbon dioxide according to the general chemical equation QHy x yl4 02 xC02 yl2HzO. 4 Conversely, water and carbon dioxide are removed from the atmosphere as inorganic bicarbonate and carbonate ions in the ocean, and as new organic matter reduced carbon in forest regrowth C02 assimilation and soil carbon storage. Water exchanges associated with the carbon cycle C make a relatively...
The Question Of Higher Sea Levels Than Present During The Late Holocene
Perhaps no aspect of the famous Fairbridge curve Fairbridge, 1961,1976 so captured the attention of sea level researchers worldwide than the portrayal of sea levels higher than present throughout most of the late Holocene see Fig. 2.1 . This curve not only stood in sharp contradiction of a smooth gradual rise in sea level depicted by curves like that for the Delaware coast discussed above, but went further modern sea level had been attained by an overall decline in sea levels over the last 5000...
Oscillating Sea Level Curves The South Carolina Coast
No sea level curve for the U.S. Atlantic Coast departs more from the present model for attempting to reconstruct a record of late Holocene sea level change than that of Colquhoun and his colleagues Fig. 2.9 . This curve, the first version of which was published almost 20 years ago Colquhoun et al. 1980 , THOUSANDS OF RADIOCARBON YEARS BEFORE PRESENT THOUSANDS OF RADIOCARBON YEARS BEFORE PRESENT Figure 2.9 Holocene sea level curve for the South Carolina coast by Colquhoun and Brooks 1986 ....
The Late Holocene Sea Level Record
In 1961 Rhodes Fairbridge published what has become the most widely known curve for global changes in middle to late Holocene sea levels Fairbridge, 1961 Fig. 2.5 . Though Fairbridge long ago acknowledged the primitive character of early versions of the curve Fairbridge, 1995 , which led to a number of revisions cf. Fairbridge, 1976 , it is still the notion of oscillating sea levels so boldly presented in his original curve that sparks debate. As recently as the late 1980s, the straw man of the...
Transgressive Sequences
Worldwide the history of Holocene sea level change is written in the sediments left as a trace of its progress across continental shelves. The nature of these sequences varies by coastal type and locale, and the breadth of deposits and their possible interpretation would easily require a separate chapter. However, whatever the coast, transgressive sequences are generally the only way information can be obtained on sea level changes predating the last several millennia, when sea levels often...
Tide Gauges and Satellite Altimetry
Long-term sea level change has ordinarily been estimated from tide gauge data. However, two fundamental problems are encountered using tide gauge measurements for this purpose. First, tide gauges only measure sea level change relative to a crustal reference point, which may be moving vertically at rates comparable to the true sea level signals Douglas, 1995 . Second, tide gauges have limited spatial distribution and suboptimal coastal locations Barnett, 1984 Groger and Plag, 1993 and thus...
Seepage Losses in Reservoirs
Seepage losses also diminish the volume of water in reservoirs. The magnitude of these losses is related to the permeabilities of the enclosing bed rocks, Reduction in Reservoir Capacity due to Siltation Reduction in Reservoir Capacity due to Siltation Sennar Makwar Reservoir , Blue Nile, Sudan Roseires Reservoir, Blue Nile, Sudan Khashm-el-Girba Reservoir, Atbara River, Sudan Data sources Shahin, 1993 Rao and Palta, 1973 Dendy et al., 1973 Smith et al, 1960 Douglas, 1990 James and Kiersch,...
History of Satellite Altimetry
NASA's satellite altimetry program was originally formulated at the 1969 Williamstown Conference Kaula, 1970 . An altimeter was actually used to scan the Moon by Apollo 14 Kaula et al, 1974 . The first altimeter used for experimental Earth measurements was operated on the Skylab manned space station McGoogan et al., 1974 . The first altimeter on an unmanned satellite was the Geodynamics Explorer Ocean Satellite 3 GEOS-3 , launched in 1975 Stanley, 1979 . Geos-3 provided useful data on eddy...
Global Properties Of Presentday Signatures Of The Gia Process Tuning The Model
Since the solutions of the SLE that are of interest insofar as their predictions of present-day rates of sea level change are concerned are clearly those based upon models of the radial viscoelastic structure of the planet that best reconcile the available data base of geological timescale observations, it is clearly important to first establish that the theory embodied in the SLE does indeed satisfy these long timescale constraints when its physical properties are appropriately selected. The...
Spatial Variations
We can gain further insight into the cause of the observed mean sea level variations by examining the spatial variations in sea level change that contribute to the global mean. While variations in global mean sea level have great scientific and public interest as a barometer of environmental change, the true scientific and social implications will be determined by the spatial patterns of sea level change. As an example, anthropogenic-induced climate change, while likely to cause a rise in...
THE ALTIMETER MEASUREMENT Measurement Description
The first point to make about satellite altimeter data is that they are not simply the product of an instrument, but come from a measurement system. Several different observations need to be made to produce high-quality sea surface heights, and maintaining the quality of the final height observations requires high performance by all components of the system. As we proceed through this discussion of the various components, we will also briefly address the errors associated with each component,...
Giadecontaminated Tide Gauge Estimates Of The Rate Of Global Sea Level Rise
For the purpose of producing the best tide gauge-based estimate of the global rate of relative sea level rise which is not contaminated by the influence of the glacial isostatic adjustment process, I will focus first upon the results obtained by applying the highest resolution version of the ICE-4G VM2 model for which results have been computed. These results are presented in Table 4.1 in which analyses are shown for 27 tide gauges, each of which is characterized by more than 70 years of...
Bruce C Douglas t Michael S Kearney Stephen P Leathermanf
DEPARTMENT OF GEOGRAPHY UNIVERSITY OF MARYLAND COLLEGE PARK, MARYLAND INTERNATIONAL HURRICANE CENTER FLORIDA INTERNATIONAL UNIVERSITY MIAMI, FLORIDA San Diego San Francisco New York Boston London Sydney Tokyo Sharp's Island, Maryland, ca. 1950. This photo shows what remained of an island that probably was approximately 700 acres in size at the time of original settlement in the late 17th century, and that still covered almost 600 acres in 1850. Until the first decades of the 20th century,...
Sea Level And The Geoid
The planar-appearing ocean surface stands in immense contrast to that of the land, where the tallest mountain peaks are more than 8 km in elevation above sea level. Beneath the ocean surface, similarly tall mountains called sea mounts also exist, and the ocean depth at some great trenches is greater than the height of the tallest mountains. The almost featureless ocean surface thus has an obvious appeal as an elevation reference. The ocean surface does exhibit some height variability. There are...