Featured Research

from universities, journals, and other organizations

Seismic Rocker Aims To Cut The Noise

Date:
February 28, 2005
Source:
Natural Sciences And Engineering Research Council
Summary:
A Canadian seismologist is arguing that our understanding of the structure of the Earth's interior is based on the equivalent of fuzzy ultrasound images that leave room for improvement.

A Canadian seismologist is arguing that our understanding of the structure of the Earth's interior is based on the equivalent of fuzzy ultrasound images that leave room for improvement.

Once seismic images are fine-tuned to remove background noise, they may tell a very different story of the world below, says Dr. Felix Herrmann, a seismologist at the University of British Columbia. And oil companies are already lining up to cash in on his clearer view of the Earth's underbelly.

Dr. Herrmann says that there has been a push to gather more data from beneath the ground through initiatives such as US ARRAY, but that these data cannot be properly used without a better understanding of how seismic images are produced.

Until now, he says, scientists have interpreted transitions in the mantle in terms of changes in a complex cocktail of substances below the earth’s surface. However, he says, his research has led to a theory that, instead of this accepted complex mineralogical composition, the seismic data could be showing a complex interplay of only two different types of substances.

“Think of what happens when you mix a French and a Swiss cheese,” says Dr. Herrmann. “You have Swiss cheese and you start to mix in more and more French cheese. At some point, you would call it a French cheese. When this happens, basically there is a critical point. That's a point where all of a sudden the material starts to become like the French cheese – and a sharp transition occurs, whose fine structure we hope to observe from noisy seismic data.”

He will present the results of his latest seismic imaging research at the 2005 American Association for the Advancement of Science meeting in Washington D.C. on February 19.

With seismic imaging, scientists bounce sound waves into the Earth, or record natural tremors, and use the reflected waves to construct an image of the Earth's interior structure in much the same way that ultrasound technology enables us to peer into the womb and see a fetus.

But Dr. Herrmann says that previous seismic images of the Earth's interior were distorted by noise. Noise is created by things like tremors, wind or even a truck driving on the surface, as well as by flaws in measuring devices and mathematical models.

As a result, while we were expecting to be painting in geological blue, we should really be thinking in an earthy pink. “What I'm proposing is certainly a different way of thinking,” says Dr. Herrmann.

While the scientific world has yet to fully adopt Dr. Herrmann's view, oil companies are eagerly taking a closer look at his “de-noising” and mixture-model techniques. His seismic imaging research has led to a recent partnership with four large oil companies to use these clearer imaging techniques to find the world's most elusive oil patches.

“Oil prices are not high for nothing,” notes Dr. Herrmann. “It's more and more difficult to find petroleum resources. The big oil fields have been found, and now people want to find smaller fields. That means we need to look with a finer resolution, and also to look deeper.”

“We also need to better understand what we see in these images,” he adds.

“That’s where both the ‘cheese model’ and noise come in, because noise limits how fine a structure you can actually resolve to learn about these rapid changes in the Earth’s properties.”

Dr. Herrmann's new theory of the earth’s transitions, co-written with MIT's Dr. Yves Bernabι, was published in the December 2004 issue of Geophysical Journal International.

Dr. Herrmann's research is supported by Science and Engineering Research Canada (NSERC).


Story Source:

The above story is based on materials provided by Natural Sciences And Engineering Research Council. Note: Materials may be edited for content and length.


Cite This Page:

Natural Sciences And Engineering Research Council. "Seismic Rocker Aims To Cut The Noise." ScienceDaily. ScienceDaily, 28 February 2005. <www.sciencedaily.com/releases/2005/02/050223150600.htm>.
Natural Sciences And Engineering Research Council. (2005, February 28). Seismic Rocker Aims To Cut The Noise. ScienceDaily. Retrieved July 23, 2014 from www.sciencedaily.com/releases/2005/02/050223150600.htm
Natural Sciences And Engineering Research Council. "Seismic Rocker Aims To Cut The Noise." ScienceDaily. www.sciencedaily.com/releases/2005/02/050223150600.htm (accessed July 23, 2014).

Share This




More Earth & Climate News

Wednesday, July 23, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Observation Boat to Protect Cetaceans During Ship Transfer

Observation Boat to Protect Cetaceans During Ship Transfer

AFP (July 22, 2014) — As part of the 14-ship convoy that will accompany the Costa Concordia from the port of Giglio to the port of Genoa, there will be a boat carrying experts to look out for dolphins and whales from crossing the path of the Concordia. Duration: 01:02 Video provided by AFP
Powered by NewsLook.com
New Orleans Plans to Recycle Cigarette Butts

New Orleans Plans to Recycle Cigarette Butts

AP (July 21, 2014) — New Orleans is the first U.S. city to participate in a large-scale recycling effort for cigarette butts. The city is rolling out dozens of containers for smokers to use when they discard their butts. (July 21) Video provided by AP
Powered by NewsLook.com
Shark Sightings a Big Catch for Cape Tourism

Shark Sightings a Big Catch for Cape Tourism

AP (July 21, 2014) — A rise in shark sightings along the shores of Chatham, Massachusetts is driving a surge of eager vacationers to the beach town looking to catch a glimpse of a great white. (July 21) Video provided by AP
Powered by NewsLook.com
Spectacular Lightning Storm Hits London

Spectacular Lightning Storm Hits London

AFP (July 19, 2014) — A spectaCular lightning storm struck the UK overnight Friday. Images of lightning strikes over the Shard and Tower Bridge in central London. Duration: 00:23 Video provided by AFP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
 
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:  

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:  

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile iPhone Android Web
Follow Facebook Twitter Google+
Subscribe RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins