Researchers take advantage of satellite imagery to understand patterns of behavior of volcanoes and prevent disasters
Constant monitoring of volcanoes could help identify and prevent natural disasters(Foto: ARCHIVO )
Tuesday June 14, 2011 Redacción | El Universal 05:15
A group of researchers from the National Polytechnic Institute (IPN) the National University Autonomous of Mexico (UNAM) and the California Institute of Technology (CALTECH), work on the detection of emissions of volcanic products, such as sulfur dioxide (SO2) and ashes to determine the type of behavior of a volcano and to predict explosive events.
According to the research group, the satellite remote sensing techniques "allow monitoring of eruptive activity of volcanoes. These techniques are a valuable tool because of its ability to observe large areas quickly and safely," say in an article in the journal Geophysics.
The system used, known as MODIS (Spectroradiometer Moderate Resolution Imaging), is aboard the Aqua and Terra satellites, both in charge of NASA, and works with an optical sensor.
This technology allowed researchers to obtain periodic emissions of SO2, a gas associated with the internal processes of the volcano. With the information gathered, could also compare the explosive activities characterized by ash emission, indicative of eruptive activity.
By analyzing the images and the quantification of volcanic products, could establish a possible relationship between explosive events and the increase in emissions of SO2.
While emissions of ash are less dramatic eruptions, they can be tremendously disruptive, especially for commercial aviation. Therefore, the research that tracked the ash and gases carried by the wind a great interest, because such information can help identify areas likely to be affected, and even warn of air navigation.
Evidence of an eruptive process
According to the engineer José Carlos Jimenez Escalona, a researcher at the ESIME-IPN and coauthor of the study, the activity of a volcano eruption is related to processes that occur inside, especially with the addition of magmatic material to the inner chambers the volcano.
"The ducts connected to the crater or volcano craters contain large amounts of gases. The addition of magmatic material results in alterations in the behavior of volcanic gas emissions," said Jimenez Escalona in an interview.
The researchers gave particular attention to the behavior of SO2, it detected a significant increase in the flow of this gas (degassing), followed by a period of emission reduction, which ultimately triggers a volcanic eruption.
According to his hypothesis, this phenomenon is due to changes in the viscosity of magma after a heavy degassing and / or "sealed" partial duct decompression, which accumulates energy that eventually will be released by explosion .
The study of the Colima Volcano
While the study shows a relationship between a significant increase in emissions of SO2 and explosive events accompanied by ash emissions (with a difference of approximately two days between an event and another), Jimenez Escalona noted that each volcano behaves particularly due to the type of material they are fed cameras and internal passages.
"In the case of Volcán de Fuego de Colima and the relationship between the two events, is an appreciation in a very short time. Just one of the studies I'm currently developing is the analysis to a longer period, which could be up to a year, "he said.
The research, published under the title Use of MODIS images to study eruptive clouds from Volcán de Fuego de Colima (México) and applications on volcano monitoring, for 36 days analyzed the behavior of the volcano with 113 images (selected from a total of 148) thrown by the MODIS system in 2005.
To detect the ash analyzed for thermal emission bands between 31 and 32 of the 36 sensor is capable of capturing the electromagnetic spectrum.
On the other hand, a simulation model called RADIANNET be able to calculate the mass and area of volcanic clouds.
As for the measurement of SO2, quantification depends on software developed by Vincent Realmuto, a researcher at Caltech and a coauthor of the study, which considers the height and width of the column SO2, temperature and atmospheric pressure, among other things.
The research, which also participates Hugo Delgado Granados, Institute of Geophysics, UNAM, further states the necessary combination of regular monitoring of emissions to other volcanic sources, such as those related to seismicity.
However, despite the fact that satellite monitoring is a safe and economical method, there are still some problems such as image resolution and the time intervals between one image and another, for example.
In Mexico, the use of this type of satellite technology is being introduced gradually for monitoring and identification of forest areas, fire detection and weather phenomena, but its application to volcanic monitoring is relatively new.
According to the research group, the satellite remote sensing techniques "allow monitoring of eruptive activity of volcanoes. These techniques are a valuable tool because of its ability to observe large areas quickly and safely," say in an article in the journal Geophysics.
The system used, known as MODIS (Spectroradiometer Moderate Resolution Imaging), is aboard the Aqua and Terra satellites, both in charge of NASA, and works with an optical sensor.
This technology allowed researchers to obtain periodic emissions of SO2, a gas associated with the internal processes of the volcano. With the information gathered, could also compare the explosive activities characterized by ash emission, indicative of eruptive activity.
By analyzing the images and the quantification of volcanic products, could establish a possible relationship between explosive events and the increase in emissions of SO2.
While emissions of ash are less dramatic eruptions, they can be tremendously disruptive, especially for commercial aviation. Therefore, the research that tracked the ash and gases carried by the wind a great interest, because such information can help identify areas likely to be affected, and even warn of air navigation.
Evidence of an eruptive process
According to the engineer José Carlos Jimenez Escalona, a researcher at the ESIME-IPN and coauthor of the study, the activity of a volcano eruption is related to processes that occur inside, especially with the addition of magmatic material to the inner chambers the volcano.
"The ducts connected to the crater or volcano craters contain large amounts of gases. The addition of magmatic material results in alterations in the behavior of volcanic gas emissions," said Jimenez Escalona in an interview.
The researchers gave particular attention to the behavior of SO2, it detected a significant increase in the flow of this gas (degassing), followed by a period of emission reduction, which ultimately triggers a volcanic eruption.
According to his hypothesis, this phenomenon is due to changes in the viscosity of magma after a heavy degassing and / or "sealed" partial duct decompression, which accumulates energy that eventually will be released by explosion .
The study of the Colima Volcano
While the study shows a relationship between a significant increase in emissions of SO2 and explosive events accompanied by ash emissions (with a difference of approximately two days between an event and another), Jimenez Escalona noted that each volcano behaves particularly due to the type of material they are fed cameras and internal passages.
"In the case of Volcán de Fuego de Colima and the relationship between the two events, is an appreciation in a very short time. Just one of the studies I'm currently developing is the analysis to a longer period, which could be up to a year, "he said.
The research, published under the title Use of MODIS images to study eruptive clouds from Volcán de Fuego de Colima (México) and applications on volcano monitoring, for 36 days analyzed the behavior of the volcano with 113 images (selected from a total of 148) thrown by the MODIS system in 2005.
To detect the ash analyzed for thermal emission bands between 31 and 32 of the 36 sensor is capable of capturing the electromagnetic spectrum.
On the other hand, a simulation model called RADIANNET be able to calculate the mass and area of volcanic clouds.
As for the measurement of SO2, quantification depends on software developed by Vincent Realmuto, a researcher at Caltech and a coauthor of the study, which considers the height and width of the column SO2, temperature and atmospheric pressure, among other things.
The research, which also participates Hugo Delgado Granados, Institute of Geophysics, UNAM, further states the necessary combination of regular monitoring of emissions to other volcanic sources, such as those related to seismicity.
However, despite the fact that satellite monitoring is a safe and economical method, there are still some problems such as image resolution and the time intervals between one image and another, for example.
In Mexico, the use of this type of satellite technology is being introduced gradually for monitoring and identification of forest areas, fire detection and weather phenomena, but its application to volcanic monitoring is relatively new.
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