Sentences with phrase «subsidence rates of»

In this study for Geology, Makan Karegar and colleagues use precise Global Positioning System (GPS) data to measure subsidence rates of the Mississippi Delta.

So far, the results suggest subsidence rates of some 9 millimeters per year in the southwest, and just 2 — 4 in the southeast.

The subsidence rate of many coastal areas is high — 5 to 10 times the mythical «sea rise».

Not exact matches

Beyond sea level rise, San Francisco is slowly sinking at a rate of up to 10 millimeters per year in a process called subsidence.

The researchers also analyzed how subsidence rates varied along adjacent 30 - meter sections of track.

The results show that the metro is particularly vulnerable to highly variable rates of subsidence, says Cathleen Jones, a radar scientist at NASA's Jet Propulsion Laboratory in Pasadena, California.

Studies have shown that coastal subsidence has been highest in some areas with the highest rates of extraction.

Earth - shaking change Whatever the current rate of subsidence, it may not reflect the full scale of the problem.

In the Mississippi Delta, where rates of land loss are especially severe, subsidence of the land surface reflects natural processes, such as sediment compaction and crustal loading, but this is exacerbated by anthropogenic withdrawal of fluids (water, oil, natural gas).

Thus, induced seismicity can be caused by injecting fluid into the subsurface or by extracting fluids at a rate that causes subsidence and / or slippage along planes of weakness in the earth.»

Accurate estimates of the current rate of subsidence in the Mississippi Delta (southern USA) are important for planning wetland restoration and predictions of storm surge flooding.

The southern portion of the delta continues to experience high rates of subsidence (5 to 6 mm per year).

The current rate of relative sea - level rise (the combined effect of land subsidence and sea - level rise) along parts of the coastal delta is nearly 8 to 9 mm per year.

I recently researched causes of subsidence in Bangladesh (Brown and Nicholls 2015) and struggled with the uncertainties, data errors, and in some cases, poor science when recording rates of subsidence.

«Data from GPS measurements and carbon dating of marsh sediments indicate that regional land subsidence in response to glacial isostatic adjustment in the southern Chesapeake Bay region may have a current rate of about 1 mm / yr (Engelhart and others, 2009; Engelhart and Horton, 2012).

Most of the Middle Mississippi River levees are currently rated Unacceptable (like 44.5 % of rated levee miles nationwide); plus there are major geotechnical issue documented by our research — subsidence and compaction and un-permitted levee modifications using road gravel that is unsuited to flood control.

A continuation of these high rates of subsidence is likely to put much of the densely populated coastal areas below relative sea level within a few decades.

Hereabouts, subsidence accounted for about half the «alarming» rate of sea level rise along the coast as measured by tide gauges.

People living near Kostolac — with houses close to the opencast mine which feeds the power plant — say there is a high rate of respiratory disease in the area; houses have also been damaged by land subsidence.

This rate was significantly lower than the 1.2 inches / year calculated by Stephens and Johnson (1951), and Shih et al. (1998) speculated that maintenance of higher water tables after 1978 was one of the major reasons for the observed reduction in the subsidence rate.»

Based on all of these studies, Stephens and Johnson (1951) concluded that the subsidence rate would be one foot per decade assuming that the water table is maintained at an 18 — 24 inch depth.

Most countries in South, South East and East Asia are particularly vulnerable to sea level rise due to rapid economic growth and coastward migration of people into urban coastal areas together with high rates of anthropogenic subsidence (for example due to water extraction) in deltas where many of the densely populated areas are located.

The lower Chesapeake Bay is especially at risk due to high rates of sinking land (known as subsidence).96 Climate change and sea level rise are also likely to cause a number of ecological impacts, including declining water quality and clarity, increases in harmful algae and low oxygen (hypoxia) events, decreases in a number of species including eelgrass and seagrass beds, and changing interactions among trophic levels (positions in the food chain) leading to an increase in subtropical fish and shellfish species in the bay.66

The authors observe that wide variations in rates of tectonic uplift and subsidence in different locations around the world at particular times mean no effective coastal management plan can rest upon speculative computer projections regarding an idealised future global sea level, such as those provided by the United Nations» Intergovernmental Panel on Climate Change (IPCC).

Thousands of new water wells have been constructed on an emergency basis over the past year, and skyrocketing rates of groundwater pumping have led to rapid land subsidence in the San Joaquin Valley.

The highest rates of subsidence occurred in the northern delta and in regions where natural gas and groundwater extraction is booming, such as the Menoufia Governorate and the Abu Madi gas field.

The U.S. Geological Survey (USGS), DWR, HydroFocus and the University of California at Berkeley have been studying subsidence and GHG emissions of rice and managed wetlands in the delta since the 1980s and have documented very high rates of primary productivity in wetlands.

However, within the northwestern Gulf of Mexico, subsidence contributes to relative sea - level rise with rates in east Texas as high as 6.0 mm / yr (Paine, 1993).

As coastal communities have become aware of the problems associated with groundwater depletion and coastal subsidence, the rate of local sea level rise has slowed, at Galveston at least (Paine et al., 2012, GCAGS Journal 1:13 - 26), so the likely sea level rise is even less than the corrections above would imply.

Although fluctuating sea level rises over the past several centuries have averaged about 7 inches, and continue to rise at that rate with no evidence of acceleration, land subsidence and hurricane risks are ever - present issues that must be taken into account.

The risk rating analyses and determines the level of threat that subsidence poses at a specific postcode, and is based on extensive subsidence insurance claims data from Property Assure.