G53A-0625
Faults Activities And Crustal Deformation near Hualien City, eastern Taiwan Analysed By Persistent Scatterer InSAR
Hualien is located in eastern part of Taiwan, and is the collision boundary in the northern of Huatung Longitudinal Valley between the Philippine Sea tectonic plate and Eurasian tectonic plate(Biq, 1981; Barrier and Angelier, 1986). There are several active faults, such as Milun fault, Beipu fault and Minyi fault, pass through the Hualien city, and create many crustal deformation. According to previous researches (Hsu, 1956; Lin, 1962; Yu, 1997) we know Milun fault is a thrust and left lateral fault, and the fault plane incline to east. Minyi fault also is a left lateral and a slight reverse fault, but it¡|s fault plane incline to west. (Chang, 1994; Yu, 1997) We applied the Persistent Scatterer Interferometric Synthetic Aperture Radar (PSInSAR, Hooper, 2007) to observe temporally-variable processes of Hualien city between 2004 to 2008. At the same time, precise leveling and GPS data were taken for the auxiliary data to verify the deformation rate and pattern in this area. In the Hualien city area, our observation showed that the active faults separate this area into several distinct blocks. Most of the blocks moved slowly, but the hanging wall of the Milun fault decreases 5- 8mm in line of sight (LOS) direction between 15 May 2004 to 24 Feb 2007, then increases 3-6mm in LOS between 1 Dec 2007 to 5 Jan 2008. The deformation reversed its direction in 2007. The western surface of Hualien City displays continuous deformation about 1.5-2mm/yr , which spread along the Beipu fault. Our preliminary investigation indicated that between late 2004 and middle 2005 there had been an abrupt increase in seismicity, which coincided with PSInSAR observation of a large displacement. The distribution of shallow source earthquakes correlate with the area with large deformation. Our following works include continuing observation of the Hualien City, and decipher the relationship between earthquakes and surface deformation, and model the fault action in Hualien City with time series.
G53A-0626
Coseismic deformation of the 2007 Sumatra earthquakes from InSAR
On the 12 September 2007 magnitude 8.5 and 7.9 earthquakes occurred in Southern Sumatra as the result of thrust faulting on the subduction zone of the Indo Australian plate under the Sunda plate. The magnitude 8.5 earthquake, located 130 km SW of Bengkulu, Sumatra, is the fourth earthquake of magnitude greater than 7.9 on this plate boundary during the past decade. The magnitude 7.9 earthquake occurred about 12 hour later and about 225 km northwest of the magnitude 8.5 earthquake. We examine the deformation caused by these earthquakes on the Sumatra islands using InSAR data. The SAR interferogram obtained from ALOS-PALSAR data acquired on January 29, 2007 and September 16, 2007 shows a significant crustal deformation in Bengkulu although the epicenter is located more than 100 kilometers westward. The deformation reaches more than 60 cm toward the satellite located 75 kilometers northwestward from Bengkulu. Westward, the Pagai islands deformation (South Pagai Island: Pulau Pagai Selatan and North Pagai Island Pulau Pagai Utara) is studied with an interferogram obtained from data of the June 21, 2007 and September 21, 2007. These islands are closer to the earthquake source fault so the maximum crustal deformation is more significant and reaches approximately 1.8m. This deformation occurs between the south end of the South Pagai Island and the north end of the North Pagai Island, meaning that the South island has moved 1.8m toward the satellite relative to the North Island.
G53A-0627
Yellowstone Deformation from 1992 to 2008: ERS, ENVISAT and RADARSAT InSAR Observations
As one of the most concentrated regions of volcanic and seismic activity in North America, Yellowstone is not only a critical region in which to study active crustal processes, but also to monitor hazardous events that could potentially affect millions of residents. The Yellowstone caldera has experienced several recent episodes of uplift and subsidence associated with volcanic, hydrothermal, and/or seismic activity. Previous Global Positioning System (GPS) work shows the caldera was recently subsiding until mid 2004, and then a new episode of uplift has occurred with rapid rates up to 7 cm/yr. This ongoing uplift is three times faster than previously measured rates of inflation in Yellowstone, suggesting a need for regular monitoring of crustal deformation that may result in hazardous seismic, volcanic, or hydrothermal events. In this study, we employ Synthetic Aperture Radar Interferometry (InSAR) data acquired by the European Radar Satellites (ERS), the Environmental Satellite (ENVISAT), and the Canadian Radar Satellites (RADARSAT) to: 1) monitor and resolve the vertical and horizontal components of crustal deformation in Yellowstone during 1992-2008, and 2) inversely model the observed deformation in the region and infer its source parameters. Results from this InSAR investigation provide new insight into the link between active tectonics and the spatio-temporal evolution of the complex Yellowstone volcanic system.
G53A-0628
Study of the 6 August 2007 Crandall Canyon mine (Utah, USA) collapse from ALOS PALSAR InSAR
We use Advanced Land Observing Satellite (ALOS) Phased Array type L-band Synthetic Aperture Radar
(PALSAR) interferometric synthetic aperture radar (InSAR) images to study land surface deformation over
the Crandall Canyon mine in Utah, which collapsed on 6 August 2007 and killed 6 miners and 3 rescuers.
The collapse was coincident to a local magnitude 3.9 earthquake. An InSAR image that spans the collapse
shows subsidence of 20-25 cm over the Crandall Canyon mine. InSAR observation of the ground surface
deformation over the Crandall Canyon mine has determined the location of the collapsed mine, suggested
the mislocation for the 6 August 2007 earthquake from the standard epicenter relocation method, and
estimated the extent of the collapsed area. These results complement the seismic investigation of the 6
August 2007 earthquake. Furthermore, modeling the ground surface deformation requires a significant
amount of fault slip in addition to the volumetric compression.
http://volcanoes.usgs.gov/insar
G53A-0629
SAR Image Coregistration Based on Topography and Deformation
L-band repeat-pass InSAR has been getting scientists' attention for its penetration depth through dense vegetation, revealing the ground deformation under the canopy of forest. This makes it possible to achieve a good coverage of volcanic activities in tropical areas such as Hawaii, Galapagos, and Indonesia. Another advantage of L-band InSAR is its tolerance to a large baseline. The critical baseline scales with the wavelength, and practically a baseline of over 1 km often produces interferograms. However, the large baseline causes parallax in the presence of topography, which appears as pixel shift between master and slave images that sometimes leads to a severe decorrelation. Using ALOS PALSAR data of Java Island, Indonesia, and intermediate files produced by ROI_PAC, we correct this parallax before forming an interferogram to improve the interferometric coherence. We also test an automatic implementation of the 'rubber sheeting" coregistration (e.g. Yun et al., GRL, 2007) for localized large deformation that cannot be explained by polynomial fitting.
G53A-0630
GeoEarthScope Airborne LiDAR and Satellite InSAR Imagery
UNAVCO has successfully acquired a significant volume of aerial and satellite geodetic imagery as part of
GeoEarthScope, a component of the EarthScope Facility project funded by the National Science Foundation.
All GeoEarthScope acquisition activities are now complete. Airborne LiDAR data acquisitions took place in
2007 and 2008 and cover a total area of more than 5000 square kilometers. The primary LiDAR survey
regions cover features in Northern California, Southern/Eastern California, the Pacific Northwest, the
Intermountain Seismic Belt (including the Wasatch and Teton faults and Yellowstone), and Alaska. We have
ordered and archived more than 28,000 scenes (more than 81,000 frames) of synthetic aperture radar
(SAR) data suitable for interferometric analyses covering most of the western U.S. and parts of Alaska and
Hawaii from several satellite platforms, including ERS-1/2, ENVISAT and RADARSAT. In addition to ordering
data from existing archives, we also tasked the ESA ENVISAT satellite to acquire new SAR data in 2007 and
2008. GeoEarthScope activities were led by UNAVCO, guided by the community and conducted in
partnership with the USGS and NASA. Processed imagery products, in addition to formats intended for use
in standard research software, can also be viewed using general purpose tools such as Google Earth. We
present a summary of these vast geodetic imagery datasets, totaling tens of terabytes, which are freely
available to the community.
http://unavco.org
G53A-0631
Ground-Truth Results of Comparison of Airborne Lidar Bathymetry (ALB) in Subtidal Coastal Environments
Results from a recent study of the performance of ALB in the coastal waters of New Hampshire-Maine indicate a potential relationship between lidar-laser measurements and seafloor characteristics. Comparison of bottom-detection results from two different ALB systems (Tenix LADS and Optech SHOALS) in the Portsmouth Harbor, NH and offshore Gerrish Island, ME showed a striking correlation in the lack of bottom detection in shallow waters (3-25 m). This lack of bottom detection is independent of the tide state, the date of data collection and the direction of the survey flight. Multibeam-echosounder measurements (Simrad EM3002) were used as reference measurements. The multibeam results show that the commonly used assumption is incorrect that where no bottom detection was made by the lidar system, the bottom depths are deeper than their surroundings. Bathymetric and acoustic-backscatter maps from the multibeam echosounder shows that the areas of no bottom detection by lidar are shallow and are affected by the seafloor characteristic. Two potential conceptual models were developed to explain the lack of bottom detection: one is dominated by the seafloor grain size and the second one is dominated by the presence of vegetation. Underwater video imagery and bottom samples were taken from the lack-of-detection areas and their surroundings in the summer of 2008. The underwater imagery shows that in some locations aquatic vegetation is present, but its distribution was very sparse. Also, the underwater imagery shows that areas where successful ALB-bottom detection occurred, the bottom is sandy, whereas the seafloor that showed lack of detection is composed of gravel, pebbles and outcrops. Preliminary analysis characterized the sands near Gerrish Island as a grayish-olive medium- to very fine-grained sand (2 to 3.5 phi) and the sands in Portsmouth Harbor as dark yellowish-brown very fine pebble gravel to coarse sand (-1 to 1.5 phi). The areas that show a lack of detection vary in color and grain size, where the common characteristic is that all areas have pebbles, gravel or outcrops (larger than-1 phi). Preliminary conclusions show that the dominant seafloor characteristic affecting the lidar bottom detection in shallow waters is the grain size of the seafloor sediments. The color of the seafloor does not appear to affect the lidar performance as much as grain size.
G53A-0632
Utilize the Remote Sensing Image to Establish the Digital Model of Geographical Information
When the natural disaster occurs, it usually leads the change of the terrain, landscape and civil engineering structures. The complete description of the change of the land covers is helpful to the execution and promotion of the disaster rescue. Remote sensing uses the aerial platform carrying image sensors to acquire the remote sensing images from the region that the human can not reach in time. The major advantage of the remote sensing technology is that the environmental information can be obtained ready without contacting with the targets. This advantage lets the remote sensing technology provide a feasible and efficient way to investigate and identify the change of the land covers in the disaster area. In this study, we use the remote sensing technology for image interpretation and the land cover type identification. A mathematical method was developed to adjust the oblique photographs from the aerial photographs to the vertical ones. Then the supervised classification is utilized to identify the land cover types. The results show that our mathematical method provides a feasible approach to adjust the oblique photographs to the vertical ones. The total accuracy of the classification accuracy in the summer is more than 70 percentages, but less than 50 percentages in the winter. The aerial photography is demonstrated to be feasible for the identification of the land cover types in this study. Keywords:Remote sensing image, oblique photograph, vertical photograph, supervised classification.
G53A-0633
TECHNOLOGY USED FOR REALIZATION OF THE REFORM IN INFORMAL AREAS.
ORGANIZATION OF STRUCTURE AND ADMINISTRATION OF ALUIZNI Law no. 9482, date 03.03.2006 " On legalization, urban planning and integration of unauthorized buildings", entered into force on May 15, 2006. The Council of Ministers, with its decision no.289, date 17.05.2006, established the Agency for the Legalization, Urbanization, and Integration of the Informal Zones/Buildings (ALUIZNI), with its twelve local bodies. ALUIZNI began its activity in reliance to Law no. 9482, date 03.03.2006 " On legalization, urban planning and integration of unauthorized buildings", in July 2006. The administration of this agency was completed during this period and it is composed of; General Directory and twelve regional directories. As of today, this institution has 300 employees. The administrative structure of ALUIZNI is organized to achieve the objectives of the reform and to solve the problems arising during its completion. The following sectors have been established to achieve the objectives: Sector of compensation of owners; sector of cartography, sector of geographic system data elaboration (GIS) and Information Technology; sector of urban planning; sector of registration of legalized properties and Human resource sector. Following this vision, digital air photography of the Republic of Albania is in process of realization, from which we will receive, for the first time, orthophoto and digital map, unique for the entire territory of our country. This cartographic product, will serve to all government institutions and private ones. All other systems, such as; system of territory management; system of property registration ; system of population registration; system of addresses; urban planning studies and systems; definition of boundaries of administrative and touristic zones will be established based on this cartographic system. The cartographic product will be of parameters mentioned below, divided in lots:(2.3 MEuro) 1.Lot I: It includes the urban zone, 1200 km2. It will have a resolution of 8cm pixel and it will be produced as a orthophoto and digital vectorized map. 2. Lot II: It includes the rural zone, 12000km2. Orthophoto, with resolution 8cm pixel, will be produced. 3.Lot III: It includes mountainous zone, 15000km2. We will receive orthophoto, with resolution 30cm pixel. All the technical documentation of the process will be produced in a digital manner, based on the digital map and it will be the main databases. We have established the sector of geographic system data elaboration (GIS) and Information Technology, with the purpose to assure transparency, and correctness to the process, and to assure a permanent useful information for various reasons. (1.1MEuro) GIS is a modern technology, which elaborates and makes connections among different information. The main objective of this sector is the establishment of self declaration databases, with 30 characteristics for each of them and a databases for the process, with 40 characteristics for each property, which includes cartographic, geographic and construction data.