Report of GPS-99 Session 6
Space and Terrestrial Techniques for Advanced crustal Deformation Research
Session 6-1: Crustal Movements and Seismic Events
Papers presented during this session spanned a wide range of topics, and
all parts of the globe. There were papers discussing deformation in: Tokai,
Japan; California, USA; Kyushu, Japan; Maharashtra, India; Aswan, Egypt;
Nicoya, Costa Rica; Cairo, Egypt; Kozu Island, Japan; and Kinki, Japan, as
well as several theory papers.
There were 10 planned oral presentations and 15 posters. Prior to the
start of the meeting, one oral presenter cancelled and a poster presenter
was given an oral time slot. In addition, two oral papers failed to appear
at the time of their talk; and, several poster presenters failed to appear.
So, in summary, the session consisted of 8 oral presentations, and about
one dozen posters.
The meeting room was ideally sized for the audience. The room was
comfortably full for the entire session. That is, there was sufficient
space that late-comers could find a seat; but not so big that it seemed
deserted. Average attendance during the session was about 140 people.
Section 6-2: Volcanic Events, Vertical Movements, et al.
The papers in this session were focused on observations and
interpretations of vertical crustal deformations using InSAR and GPS.
Most of the session was focused on volcanic deformation with a number of
presentations related to earthquake deformation, plate boundary
deformation, Earth rotation, and ocean loading. The results presented
included observations over very short time periods of a few hours to
several years and demonstrated how GPS can be used as a high temporal
resolution observing technique both after the fact and in near
Spectacular results of volcanic deformation from volcanoes in Hawaii,
Indonesia, Japan, and the Galapagoes showed how GPS and InSAR
observations are being widely used for detecting the patterns of
deformation around volcanoes. Many of these interferopgrams had large,
symmetric signals that were interpreted with respect to Mogi source
models. However, a number of the volcanoes had more complex deformation
patterns indicative of greater spatial and temporal complexity in the
shapes of the sources, their locations and evolutions, and the
development of the volcanic edifices.
The large information content in these space geodetic data sets holds
promise for increasing our understanding of volcanic systems and for the
routine inclusion of these types of data in monitoring programs. The
papers presented showed the complimentary nature of the two space
geodetic techniques, GPS and InSAR, when they are integrated for source
determination and highlighted their strengths for volcanic hazard