2013 Esri Survey Summit

July 6–9, 2013 | San Diego, California

Vertical Crustal Motion in the

Northwestern Gulf of Mexico by Integrating
Permanent GPS, Tide Gauge and
Satellite Altimetry

Nijaz Karacic, RPLS - Pacheco Koch

Randall L. Marshall, RPLS

Esri UC2013 .
 Hello my name is Fred Flintstone and I
am here today to discuss GPS theory
for surveying in present–day times

Esri UC2013 . Esri SUR1341: VCM by Integrating GPS, TG and SA

 Outline
1. Introduction
• Intro to Vertical Crustal Motion
• Gulf of Mexico Vertical Crustal Motion
• How Can We Measure It
• Geology of the Region
2. Previous Research
3. Available Observations measuring components of VCM
• Satellite Altimetry
• In Situ Sea Level Data
• Permanent GPS CORS Data
4. Procedure and Methodology
5. Presentation And Analysis Of Results
6. Discussions and Conclusions
7.References

Esri UC2013 . Esri SUR1341: VCM by Integrating GPS, TG and SA

 Intro to Vertical Crustal Motion
Recently, observations of Vertical Crustal Motion (VCM) from
improved GPS network solutions and combined tide gauge and
satellite altimetry solutions have become available.
The determination of VCM at tide-gauge locations relies on two
observations: absolute and relative sea level change obtained from
satellite altimetry and tide gauge records, respectively.
In principle, the difference between the two sea level time series
represents VCM. In addition, GPS vertical rates provide a direct
measurement of VCM.
Mostly subsidence, compaction and consolidation of sediments,
together with large-scale tectonic processes, dominate the crustal
motion signal. The re-analysis of tide gauge, GPS, and altimetry,
with a focus on the Northern Gulf of Mexico coast, is required in
order to determine local vertical motion and its changes along the
Gulf coast.

Esri UC2013 . Esri SUR1341: VCM by Integrating GPS, TG and SA

 Intro to Vertical Crustal Motion

Ostanciaux, 2011

Global Vertical Crustal Motion rates based on difference

between records from satellite altimetry and tide gauge records.
Esri UC2013 . Esri SUR1341: VCM by Integrating GPS, TG and SA
 Intro to Vertical Crustal Motion (Cont.)

SONEL, URL5

Global Vertical Crustal Motion rates based on GPS

Esri UC2013 . Esri SUR1341: VCM by Integrating GPS, TG and SA
 How Can We Measure It

• GPS – VCM(Crustal Motion)

• Satellite Altimetry – VASL(Absolute Sea Level)

• Tide Gauges – VRSL(Relative Sea Level) (Crustal

Motion Included)

Esri UC2013 . Esri SUR1341: VCM by Integrating GPS, TG and SA

 How Can We Measure It (Cont.)

Esri UC2013 . Esri SUR1341: VCM by Integrating GPS, TG and SA

 Geology of the Region
• Houston-Galveston Area
• Southern Louisiana Area
• Mississippi Delta Area

Regional map, showing

the northwestern Gulf
of Mexico. Red dashed
lines show the eastward
migration of deposit
centers. The salt basin
extends from the
Luling-Mexia-Talco fault
zone to the Sigsbee
escarpment.
(Engelkemeir, 2008)

Esri UC2013 . Esri SUR1341: VCM by Integrating GPS, TG and SA

 Geology of the Region (Cont.)
Compaction and consolidation of young (Holocene) sediments. Older sediments
also compact, but at lower rates. Organic rich marshy sediments are susceptible
to extreme compaction when drained for agriculture or urbanization. As the
sediments desiccate, carbon-rich material oxidizes to CO2, diffusing into the
atmosphere with consequent mass and volume loss in the soil.

Subsidence due to mass loading. If sediment flux is steady, the delta attains a
state close to isostatic equilibrium. The Mississippi delta received a large
sediment load near the end of Holocene glaciation. The delayed response of the
viscous upper mantle means that the delta is still adjusting to this load, possibly
causing several millimeters per year of subsidence (Ivins et al., 2007). Clearing
the continental interior for agriculture in the past 150 years may also have
increased sediment supply and recent loading.

Tectonic subsidence. Gravity sliding (downslope movement of a delta due to the

gravitational load of the sediments) also contributes to subsidence. For the
Mississippi delta, GPS data show approximately 2 1 millimeters per year of
southward motion toward the Gulf of Mexico (Dokka et al., 2006). Associated
subsidence is less precisely known and may vary as a function of distance from
active normal faults accommodating the motion. The mean rate of GPS
measured delta subsidence (5 2 millimeters per year (Dokka et al., 2006)
represents the sum of several effects, including mass loading and tectonic
subsidence.
Esri UC2013 . Esri SUR1341: VCM by Integrating GPS, TG and SA
 Previous Research
1. Nerem and Mitchum (2002) Legend:

2. García et al. (2007) BLUE=TG & ALT

3. Kuo et al. (2004, 2008) RED= GPS, TG & ALT

4. Ostanciaux et al. (2011) WHITE= GPS

5. Ray et al. (2010)

6. Bouin and Wöppelmann (2010)

7. Braun et al. (2007)

8. Santamaría-Gómez et al. (2011)

9. Dokka at al. (2006)

Esri UC2013 . Esri SUR1341: VCM by Integrating GPS, TG and SA

 Previous Research (Cont.)
Nerem and Mitchum (2002) evaluated the differences between the absolute
and relative sea level change from satellite altimetry and tide gauge records.
This earlier study is of course based on a shorter time span (1992–2001) and
a shorter database.
García et al. (2007) used data from approximately the same period but
instead focused on the Mediterranean Sea, where Nerem and Mitchum
(2002) did not include any data.
Kuo et al. (2004, 2008) combined the regional mean sea level, tide gauge
and altimetry data, and long tide gauge records.
Ray et al. (2010) released the latest comparison of DORIS data with
estimates of VGM rates derived from satellite altimetry and tide gauge
records (from 1992 to 2009) for selected data points.
Bouin and Wöppelmann (2010) carried out a study of global accuracy on the
basis of GPS data in comparison with estimates of VGM rates inferred from
tide gauge records and the mean absolute sea level.

Esri UC2013 . Esri SUR1341: VCM by Integrating GPS, TG and SA

 Previous Research (Cont.)
Santamaría-Gómez et al. (2011) focuses on the effects of time correlation in
weekly GPS position time series on velocity estimates and demonstrated that
correlated noise content with homogeneously reprocessed data is dependent
on time series length and, especially, on data time period and showed that
the data period dependency cannot be explained by the increasing tracking
network or the ambiguity fixation rate but is probably related to the amount
and quality of recorded data.
Braun et al. (2007) compares vertical motion observations with predictions
obtained from 70 different GIA models and showed that both sets of
independent observations (tide gauges/altimetry and GPS) are highly
correlated and showed very similar fit to the models.
Ostanciaux et al. (2011) computed VGM rates by combining tide gauges
records and local satellite altimetry, compared this database to previous
studies that use geodetic techniques and tide gauges records in order to
evaluate the consistency of their results and previous ones.
Dokka at al. (2006) defined tectonic control of subsidence and southward
displacement of southeast Louisiana with respect to stable North America.

Esri UC2013 . Esri SUR1341: VCM by Integrating GPS, TG and SA

 Available Observations
Satellite Altimetry Data

VASL - Absolute
Sea Level

Data derived from global satellite measurements

obtained from CLS/CNES/Legos
Esri UC2013 . Esri SUR1341: VCM by Integrating GPS, TG and SA
 Available Observations (Cont.)
In Situ Sea Level Data

VRSL - Relative
Sea Level

Historical sea level data derived from coastal tide gauge

records obtained from CSIRO.
Esri UC2013 . Esri SUR1341: VCM by Integrating GPS, TG and SA
 Available Observations (Cont.)
Locations of CORS Sites and TGs

Locations of Permanent
CORS Sites, Tide Gauges,
and the growth faults of
the region

Esri UC2013 . Esri SUR1341: VCM by Integrating GPS, TG and SA

 Available Observations (Cont.)
Satellite Altimetry-Gulf of Mexico

Esri UC2013 . Esri SUR1341: VCM by Integrating GPS, TG and SA

 Available Observations (Cont.)
Satellite Altimetry-NW Gulf of Mexico

Esri UC2013 . Esri SUR1341: VCM by Integrating GPS, TG and SA

 Procedure and Methodology
1. Data Acquisition
• Permanent GPS CORS Site data obtained from NGS
• Tide gauges records obtained from TCOON, PSMSL and NOAA
• Satellite altimetry obtained from AVISO
• Geological Records obtained from UTD library and online from
USGS
2. Data Processing
A.GPS
• Software and algorithms developed using a Linux Shell script to
automate processing using NGS OPUS Solutions
• Results of automated processed CORS site sorted to create GPS
time series in Matlab
B. Satellite Altimetry
• Use of “Regional MSL Trend from October of 1992 – December of
2012” obtained from AVISO

Esri UC2013 . Esri SUR1341: VCM by Integrating GPS, TG and SA

 Procedure and Methodology (Cont.)
C. Tide Gauges
• Completed data processed and latest corrections as seasonal
signal applied
3. Validation of VCM with Independent Observations
• Comparison of local sea level rates with regional GoM rates
• Determine satellite altimetry time series using various numbers of
footprints closest to the TG
• Analyze retrieval accuracy between single and combined mission
• Data analysis of the provided and processed data
• Investigate several GIA Model outputs

Esri UC2013 . Esri SUR1341: VCM by Integrating GPS, TG and SA

 Procedure And Methodology (Cont.)
4. Correlation with Geological Records
• Correlation of VCM with geological indicators
• Derive vertical component of change based on all three sensors
• Perform analysis of residuals for all three sensors supported by
the tectonics of the region
5. Uncertainty assessment
• Demonstrate and confirm synergy of obtained VCM with
uncertainty assessment
• Demonstrate uncertainty assessment for individual sensors

Esri UC2013 . Esri SUR1341: VCM by Integrating GPS, TG and SA

 Presentation And Analysis Of Results
CORS Sites-Velocities

Subsidence

Uplift

Esri UC2013 . Esri SUR1341: VCM by Integrating GPS, TG and SA

 Presentation And Analysis Of Results
Tide Gauges-Velocities

Esri UC2013 . Esri SUR1341: VCM by Integrating GPS, TG and SA

 Presentation And Analysis Of Results
Satellite Altimetry

Esri UC2013 . Esri SUR1341: VCM by Integrating GPS, TG and SA

 Presentation And Analysis Of Results

Esri UC2013 . Esri SUR1341: VCM by Integrating GPS, TG and SA

 Discussions And Conclusions
1. Summary of Findings
a.) Obtained Vertical Crustal Motion (VCM) from improved GPS network
solutions and combined tide gauges and satellite altimetry solutions
b.) Performed the re-analysis of tide gauge, GPS, and altimetry, with a focus
on the Northern GoM coast including defining subsidence in all three areas
by processing permanent CORS Sites along the Northwestern Gulf of
Mexico
c.) Identified areas of significant and/or laterally changing VCM for natural
hazard assessment
d.) Defined by geological records the laterally varying rates of VCM
geological records mostly due to oil, gas or water extractions but also
influenced by larger scale tectonic motion
e.) Investigated strategies of combining different approaches, using
networks, localities, temporal coverage and emphasizing new strategies
f.) All localities allowed for the direct estimation of subsidence in the Gulf
of Mexico area and enabled the discrimination of locally varying rates

Esri UC2013 . Esri SUR1341: VCM by Integrating GPS, TG and SA

 Special Thanks to:
1. Dr. Alexander Braun
2. Jacob Maggard
3. Scott Shumate

Esri UC2013 . Esri SUR1341: VCM by Integrating GPS, TG and SA

 References
[1] Anderson,2007, [2] AVISO, [3] Ballua et al.,2011, [4] Bird et al.,2005,
[5] Bouin et al.,2010, [6] Braun&Fotopoulos,2007, [7] Braun et al.,2008,
[8] Cazenave et al.,1999, [9] Cazenave et al.,2003, [10] Cazenave et al., 2008,
[11] Church et al.,2010, [12] Church et al.,2011, [13] Dixon et al.,2008,
[14] Dokka et al., 2006, [15] Engelkemeir&Khan,2008, [16] Fu,2009,
[17] García et al.,2007, [18] Holzer,1987, [19] IPCC,2007, [20] Ivins,2007,
[21] Jacob at al.,2012, [22] Kuo et al.,2004, [23] Kuo, et al.,2008,
[24] Mazzotti, et al.,2003, [25] Mazzotti et al.,2007, [26] Merrifield et al.,2010,
[27] Morton et al.,2002, [28] Nerem&Mitchum,2002, [29] NOAA,
[30] Ostanciaux, 2011 [31] Ray et al., 2010, [32] Santamaría-Gómez et al.,2011,
[33] Shum et al.,2002, [34] Salvador, 1991, [35] Törnqvist et al.,2008,
[36] Williamson,1959, [37] Winker,1982, [38] Wöppelmann et al.,2007,
[39] Wöppelmann et al.,2009, [40] Wöppelmann&Marcos,2012

Esri UC2013 . Esri SUR1341: VCM by Integrating GPS, TG and SA

 Discussion/Questions

Esri UC2013 . Esri SUR1341: VCM by Integrating GPS, TG and SA