Shifting land won't stop your journey: Using satellites to watch for land hazards

Date: June 25, 2014

Source: European Space Agency

Summary:

Subsidence, rockfalls and landslides threaten potentially devastating human and economic consequences across Europe -- but satellites can help. Traditional monitoring such as photographic mapping to measure changes in the landscape works well for specific locations but is labour intensive and costly. Now, the European Space Agency has looked at using satellites to watch for hazards across broad areas that could affect road and rail networks.

Subsidence along Val Nalps in Switzerland. Results on the left are obtained from ERS-1/2 data from 1992 to 2000; the results on the right are from Envisat data from 2004–10. Credit: MATIST

Subsidence, rockfalls and landslides threaten potentially devastating human and economic consequences across Europe -- but satellites can help.

Traditional monitoring such as photographic mapping to measure changes in the landscape works well for specific locations but is labour intensive and costly. Now, ESA has looked at using satellites to watch for hazards across broad areas that could affect road and rail networks.

The outcome is so promising that the resulting monitoring services continue to be developed by the companies involved in the two projects.

The services rely on a triple space alliance of satellite radar images , combined with satnav using satcoms to relay in-situ observations to a central system for analysing ground motion around road and rail networks.

One promising approach is to use maps produced from radar satellites to identify potentially hazardous slopes, followed by repeat monitoring at ground level.

By taking regular observations, displacements across large areas can be measured with millimetre accuracy. Any sudden changes in motion indicate a potentially high-risk situation and invite closer scrutiny.

"There is no single way of solving the problem of monitoring natural hazards," says ESA's Rob Postema, "but these two projects demonstrate how combining techniques results in a powerful toolset for tackling a whole range of geological challenges."

The Live Land study led by CGI in the UK, looked at how to combine information from satellite radar scans, geology and weather forecasts to come up with risk maps that give enough warning to reduce the disruption and cost associated with landslide and subsidence on selected roads and railways in Scotland.

For example, an area of steep slopes and wet soil that is expecting heavy rainfall is at a higher risk of a landslide -- and this would be highlighted in the maps.

Similarly, the Matist project, led by Gamma Remote Sensing and Consulting in Switzerland, combined satellite and terrestrial radar information and satnav to follow ground movements in the mountainous regions of Switzerland and Austria -- notably covering the dense rail networks and Austria's main road network.

These studies used existing Earth observation data but Europe's Sentinel satellites will become a valuable resource once they come online.

Rob Postema notes: "In coming years, I expect to see a great many more innovative applications that make use of satellite data and capabilities, such as Earth observation and satellite navigation for keeping a watchful eye on phenomena of ground motion and the associated risks."



Story Source:
Science Daily
The above story is based on materials provided by European Space Agency. Note: Materials may be edited for content and length.

Famous Film Locations on Google Earth

Where Movies Live

Which film location would you most like to see?

While most movies are filmed in comfortable studios, increasingly in front of green screens, sometimes they happen in actual places that exist. On the planet. This one. Earth. And thanks to science - or more specifically the omniscient gift of Google - we can see where they happened without even leaving home.

Click on the image above to see a few iconic film locations using the magic of Google Earth. *WARNING: Includes a handful of spoilers.*

Studying magma formation beneath Mount St. Helens

Date:         June 18, 2014
Source:      University of Washington

Summary: 
Scientists are embarking on a research expedition to improve volcanic eruption forecasting by learning more about how a deep-underground feeder system creates and supplies magma to Mount St. Helens. They hope the research will produce science that will lead to better understanding of eruptions, which in turn could lead to greater public safety.

Mount St. Helens as it appeared two years after its catastrophic eruption on May 18, 1980.

Credit: U.S. Geological Survey

University and government scientists are embarking on a collaborative research expedition to improve volcanic eruption forecasting by learning more about how a deep-underground feeder system creates and supplies magma to Mount St. Helens.

They hope the research will produce science that will lead to better understanding of eruptions, which in turn could lead to greater public safety.

The Imaging Magma Under St. Helens project involves three distinct components: active-source seismic monitoring, passive-source seismic monitoring and magnetotelluric monitoring, using fluctuations in Earth's electromagnetic field to produce images of structures beneath the surface.

Researchers are beginning passive-source and magnetotelluric monitoring, while active-source monitoring -- measuring seismic waves generated by underground detonations -- will be conducted later.

Passive-source monitoring involves burying seismometers at 70 different sites throughout a 60-by-60-mile area centered on Mount St. Helens in southwestern Washington. The seismometers will record data from a variety of seismic events.

"We will record local earthquakes, as well as distant earthquakes. Patterns in the earthquake signatures will reveal in greater detail the geological structures beneath St. Helens," said John Vidale, director of the University of Washington-based Pacific Northwest Seismic Network.

Magnetotelluric monitoring will be done at 150 sites spread over an area running 125 miles north to south and 110 miles east to west, which includes both Mount Rainier and Mount Adams. Most of the sites will only be used for a day, with instruments recording electric and magnetic field signals that will produce images of subsurface structures.

Besides the UW, collaborating institutions are Oregon State University, Lamont-Doherty Earth Observatory at Columbia University, Rice University, Columbia University, the U.S. Geological Survey and ETH-Zurich in Switzerland. The work is being funded by the National Science Foundation.

Mount St. Helens has been the most active volcano in the Cascade Range during the last 2,000 years and has erupted twice in the last 35 years. It also is more accessible than most volcanoes for people and equipment, making it a prime target for scientists trying to better understand how volcanoes get their supply of magma.

The magma that eventually comes to the surface probably originates 60 to 70 miles deep beneath St. Helens, at the interface between the Juan de Fuca and North American tectonic plates. The plates first come into contact off the Pacific Northwest coast, where the Juan de Fuca plate subducts beneath the North American plate and reaches great depth under the Cascades. As the magma works its way upward, it likely accumulates as a mass several miles beneath the surface.

As the molten rock works its way toward the surface, it is possible that it gathers in a large chamber a few miles beneath the surface. The path from great depth to this chamber is almost completely unknown and is a main subject of the study. The project is expected to conclude in the summer of 2016.

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The above story is based on materials provided by University of Washington. Note: Materials may be edited for content and length.


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University of Washington. "Studying magma formation beneath Mount St. Helens." ScienceDaily. ScienceDaily, 18 June 2014. <www.sciencedaily.com/releases/2014/06/140618163918.htm>.

University of Washington. (2014, June 18). Studying magma formation beneath Mount St. Helens. ScienceDaily. Retrieved June 19, 2014 from www.sciencedaily.com/releases/2014/06/140618163918.htm

University of Washington. "Studying magma formation beneath Mount St. Helens." ScienceDaily. www.sciencedaily.com/releases/2014/06/140618163918.htm (accessed June 19, 2014).