Ruapehu Volcano, New Zealand
Satellite Movies
1996 Eruption Images
GMS MPEG Animations 2030Z 16 June to 1330Z 17 June at one hour intervals
GMS-5 Band 1. Thermal Infrared brightness temperature
image. In this image, cold features, such as high clouds are bright
white, and warm features, such as water and land are dark. The
volcanic cloud is seen extending from the vent (red dot) to the
northeast. In the early images in this sequence, the volcanic cloud is
detected by its location realitive to the vent, its shape, and its cold
temperature. However, as the cloud detaches from the vent and drifts
away, it is difficult to discriminate it from meterological clouds.
Note that after 0830 GMT on June 17, the volcanic cloud is difficult to
distinguish from the meterological clouds. However, multispectral
image techniques allow us to discriminate ash bearing volcanic clouds,
from meterological clouds containing water and ice. (See
below)
GMS-5 Band 1 minus Band 2 350K MPEG
GMS-5 Band 1-2. Two channel thermal infrared brightness
temperature difference image. In this image, the temperature
information at two different wavelengths are used to discriminate the
volcanic cloud. Volcanic clouds generally have negitive band 1-2
temperature differences, while meterological clouds generally have
positive differences. In this image, we are able to pick the volcanic
cloud out of all of the background information, and to track it more
clearly for longer time periods.
This page maintained by Dave Schneider (djschnei@mtu.edu)