Keywords: volcano monitoring, abrupt geothermal anomaly, thermal infrared remote sensing
Abstract
Volcano eruption is one of the most serious geological disasters, however, a host of facts have
proven that Changbai mountain volcano is a modern dormant active volcano and had ever erupted disastrously.
With the rapid development of space technology such as RS (Remote Sensing) technology, GIS (Geographic
Information Systems) technology and GPS (Global Positioning System) technology, monitoring of volcano activity
has already become feasible. The paper presents a method by which volcano activities would be monitored, that is,
RS measures geothermal anomaly, GIS analyzes volcano distribution and activity pattern, and GPS monitors the
micro-deformation of crust (totally called ‘3S’ technique). Reasons for Abrupt geothermal anomaly is mainly
analyzed, and transmission mechanism of geothermal anomaly in volcanic regions are explained in detail.
1. Introduction
Changbai Mountain volcano is the biggest one in China, and one of the famous volcanoes in
the world, ever greatly erupted 1200 years ago, last eruption in about 1903. Based on its frequent
modern eruption activities, complicated magma components, huge volcanic base, high volcanic
cone, various eruption types, Changbai Mountain volcano has become a dormant active one with a
potential eruption danger.
The region is an important economic development zone of Jilin Province in China, especially
in many aspects of resources such as tourism, energy, terrestrial heat, medicine herbs, forestry and
minerals, it has huge development potentialities. However, this type of very dangerous volcano
existed have to draw an attention of all level of governments, investors and scientists. For this
reason, many scientists did a large number of research jobs in the fields of volcano geology,
volcanic kinetics, volcanic eruption materials, volcanic magma and magma movement in decades.
In other way, they applied various devices to measure and monitor the variation of geophysics and
geochemistry, for example, earthquake, geomagnetism, ground temperature and crust deformation.
With the development of space technology, especially remote sensing and global positioning
system, monitoring volcanic activities of Changbai Mountain from the space has become possible,
mainly concentrating on geothermal anomaly, geomagnetism anomaly and crust deformation. This
paper discusses thermal infrared satellite remote sensing technique applied on volcanic activities
of Changbai Mountain.
Thermal infrared detecting technology is to use thermal infrared sensor to record the data
reflected by heat objects. After correcting the data and removing noise interference, we can obtain
the temperature difference between abrupt geothermal anomalous area and normal area, and
further analyze volcanic activity trend.
2. Principles of remote sensing monitoring for abrupt geothermal anomaly in
volcanic region
2.1 Feasibility of remote sensing monitoring for abrupt geothermal anomaly in volcanic
region
Abrupt geothermal anomaly in volcanic region comes out in the forewarning period of
volcano eruption or violent volcanic activities. This type of anomalous geothermal is able to emit
electromagnetic wave by the way of various transmissions, and accepted by thermal infrared
sensors. Based on the formation transmission of abrupt geothermal anomaly, geothermal anomaly
in volcanic region should be occurred in a large area up to about a few thousand kilometers; the
temperature rises up to 6 degree centigrade, more obviously in the area of fissures or low valleys.
2.2 NOAA satellite and AVHRR data
In general, abrupt geothermal anomaly caused by volcanic activities may last a few hours or
days, therefore, high temporal meteorology satellite has to be used as an ideal monitoring base.
AVHRR data has 5 channels, in which there are two thermal infrared channels; one middle
infrared channel; another two as reflective channels. NOAA satellite uses dual-satellite system so
that the same place is taken at least 4 times every day. Its ground resolution of AVHRR data on the
nadir point is 1.1 kilometers; recorded values are 8 byte, which can represent the range of
temperature from the lowest to the highest on the earth’s surface. These features may fully meet
the need of monitoring abrupt geothermal anomaly in volcanic region. Figure 1 shows the whole
flow chart of monitoring abrupt geothermal anomaly in regions of volcano by meteorology
satellite
Fig. 1. Flow chart of monitoring abrupt geothermal anomaly
in regions of volcano by meteorology satellite
