Analysis of Crustal Movement About Antarctica
Using Distributed GPS Network
Joon-Kyu Park1, Min-Gyu Kim2 *, Jong-Sin Lee2
1
Dept. of Civil Engineering, Seoil College, SeoilDaehak-Gil-22,
Jungnang-gu, Seoul, Korea
[email protected]
2
Dept. of Civil Engineering, Graduate School, Chungnam National University
99 Daehak-ro, Yuseong-gu, Daejeon, Korea
[email protected], [email protected]
Abstract. In this study, data obtained from distributed GPS network as sensor
between 2004 and 2012 analyzed using precise point positioning. The
movement speed for each station decided based on the GPS network processing.
Each stations speed was ranged 0.3~15.2mm/year, and the standard deviation
was ranged ±0.1~±0.3 mm/year. It is expected that the crustal movement speed
of Antarctica can be used as the basic data for relevant studies on crustal
movement about global crustal movement.
Keywords : GPS network, Antarctica, Precise Point Positioning, Crustal
Movement
1
Introduction
Antarctica is a huge continent, covering 14 million square kilometers or 10 percent
of the Earth's land area. It influences an even greater area - extending beyond the
equator - in the form of cold air, water currents and migratory sea birds and marine
mammals. With an average elevation of 2,300 meters, Antarctica is the highest and
driest of all continents. It is also the coldest - the average annual temperature at the
South Pole is -49˚ Celsius. Antarctica plays a vital role in the functioning of the
global ecosystem. It should be little surprise then that Antarctica is an important place
for science - the pursuit of knowledge about the physical and natural world.1)
As GPS ensures low installation cost and high accuracy for decision of the location,
it has been recommended as an ideal sensor for a study of crustal displacement, as an
alternative to VLBI or SLR.2) Studies on crustal movement using GPS network are
being conducted on all around the earth such as Eastern Asian region including Japan,
China and Siberia, Middle European region, and Caribbean and North American
region.3)4)5) As information on the crustal movement by means of all kinds of
geophysical sensing data and GPS piles up recently, a number of studies which try to
*Corresponding
author.
AST 2013, ASTL Vol. 20, pp. 69 - 72, 2013
© SERSC 2013
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Proceedings, The 5th International Conference on Advanced Science and Technology
explain stress distribution which determines crustal displacement and characteristics
of ground movement have been introduced.6)
This study calculated crustal movement of Antarctica using distributed GPS
network. For the study, the GPS data were collected for 8 years and 6 months in the 7
IGS (International GNSS Service) CORS (Continuously Operating Reference
Stations) in Antarctica. IGS was formally recognized in 1993 by the International
Association of Geodesy (IAG), and began routine operations on January 1, 1994,
providing GPS orbits, tracking data, and other data products in support of geodetic
and geophysical research. The data were processed in the methods of PPP (Precise
Point Positioning) per week using Bernese GPS Software 5.0 (BSW5.0 afterwards).
Crustal movement of Antarctica was calculated based on sensing of position change.
2
Data Acquisition and Processing
The RINEX data were collected for the 7 CORS including Casey, Davis, Mawson
Ross Island, O'Higgins, East Ongle Island, and Vesleskarvet, which were registered in
IGS. GPS data was obtained on a weekly basis for 8 years and 6 months from July
2004 to December 2012 from Crustal Dynamics Data Information System of NASA
(National Aeronautics and Space Administration).
In data processing, the deviations occurring during sensing by GPS due to physical
movement of the earth, pole movement, atmospheric load, and ocean tidal loading
must be removed using a proper model.7) BSV5.0 eliminated these correction factors
by using precise orbiting and all kinds of models provided by NASA JPL (NASA Jet
Propulsion Laboratory), AIUB (Astronomical Institut Universität Bern). In this study,
the GPS data from the 7 CORS were processed in the methods of PPP using BSV 5.0
BPE (Bernese Processing Engine). An overview of the GPS data processing strategy
in this study is summarized in Table 1.
Table 1. Data Processing Strategy
Parameters
Software
Data Processing Methods
Observation Data
Satellite Ephemeris
Ambiguity Resolution
Tropospheric Correction
Earth Gravity Potential
Antenna Model
3
Description
BSV5.0
Precise Point Positioning
L1, L2 CODE and Phase
Precise Ephemeris
Quasi Ionosphere Free
Dry and Wet Niell Model
JGM3
Absolute Model
Analysis of Crustal Movement
In this Study, data of distributed GPS network were analyzed in order to sensing
the Antarctic movement speed. Due to most of the Antarctic continent being covered
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Analysis of Crustal Movement About Antarctica Using Distributed GPS Network
with a thick ice sheet, bedrock outcrops can only be found at coastal areas and at a
small number of mountain outcrops, where these IGS CORS are located. We analyzed
data from 7 IGS CORS to obtain coordinate solutions for 8.5 years from 2004 to
2012.
To sensing the velocity of crustal movement, GPS data was processed using PPP
method by BPE, and its result was adjusted based on July 7th, 2004 (DOY 2004.189)
fixed on the ITRF2000 coordinate system. Figure 1 coordinate time series of north
and east component of CAS1 CORS by PPP. The vertical axis of the graph is the
fluctuation amount of coordinate value on the data processed from July 7th, 2004
while horizontal axis indicates observed time.
Fig. 1. Coordinate Time Series of CAS1
Normal Equation Solution, for sensing of crustal movement velocity, created after
PPP processing was processed using ADDNEQ2 module in the method of Free
Network Solution for the entire study period. In this study, the 3 crustal displacement
models were compared with PPP result for evaluation. Table 2 shows velocity of IGS
CORS.
Table 2. Velocity of IGS CORS
Station
Name
Casey
Davis
Mawson
McMurdo
O'higgins
Syowa
Vesleskarvet
Velocity (mm/year)
North (RMSE)
East (RMSE)
ID
CAS1
DAV1
MAW1
MCM4
OHI2
SYOG
VESL
-9.40 ± 0.1
-4.90 ± 0.1
-3.00 ± 0.1
-12.10 ± 0.1
11.70 ± 0.1
1.30 ± 0.1
12.80 ± 0.2
2.20 ± 0.2
-2.10 ± 0.1
-2.10 ± 0.1
10.70 ± 0.3
15.20 ± 0.2
-2.10 ± 0.1
-0.3 ± 0.2
The Velocities of latitude and longitude direction using PPP was sensed as
0.3~15.2 mm/year in accordance with the CORS and the standard deviation ranged
±0.1~±0.3 mm/year. Considering the calculated direction of crustal movement,
Antarctica showed the aspect of rotating to the same direction as the earth rotation
centering on the outline of SYOG, MAW1 station. The speed of crustal movement
was as small as 1.30~4.90 mm/year for SYOG, MAW1, and DAV1 Station, while it
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Proceedings, The 5th International Conference on Advanced Science and Technology
was as big as 15.20 mm/year and 12.10 mm/year for OHI2 and MCM4 stations
respectively.
4
Conclusion
This study calculated crustal movement of Antarctica based on distributed GPS
network. The data were collected for 8.5 years in the 7 GPS CORS in Antarctica
among those registered in IGS and the crustal movement velocity sensed by GPS. The
results are summarized as follows:
After estimating the crustal movement speed by contributed GPS network for 8
years and 6 months from July 2004 until December 2012, crustal movement in
Antarctica was determined with average ±0.1~±0.3mm/year standard deviation. This
result confirms that use of GPS network could enable determination of crustal
movement speed with high accuracy. The assumed result of crustal movement of
Antarctica using GPS implied that Antarctica rotates as in the same direction as the
earth rotation centering on the outline of SYOG, MAW1 station. Further use of GPS
data at other stations in Antarctica together with the GPS data of the above 7 CORS
may ensure more precise analysis on the movement of Antarctica. It is expected that
the crustal movement speed of Antarctica can be used as the basic data for relevant
studies on crustal movement about global crustal movement.
Acknowledgments. This research was supported by Basic Science Research Program
through the National Research Foundation of Korea(NRF) funded by the Ministry of
Education, Science and Technology(2012-004414).
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