Using Landsat 8 Remote Sensing Data Set for Thermal ...
Transcript of Using Landsat 8 Remote Sensing Data Set for Thermal ...
Using Landsat 8 Remote Sensing Data Set
for Thermal Anomaly Mapping
at Pantar Geothermal Area, East Nusa Tenggara, IndonesiaSantia Ardi MUSTOFA1,3, Md. Bodruddoza MIA2,3, Jun NISHIJIMA3, Yasuhiro FUJIMITSU3
¹Center for Coal, Mineral, and Geothermal Resources, Ministry of Energy and Mineral Resources of the Republic of Indonesia, Bandung, Indonesia
²Department of Geology, University of Dhaka, Dhaka, Bangladesh
³Laboratory of Geothermics, Department of Earth Resources Engineering, Faculty of Engineering, Kyushu University, Fukuoka, Japan
Correspondent author: [email protected]
Identifying of alteration distribution is a preliminary study
in geothermal exploration. It can be observed when these
alteration products are exposed at the surface. The remote
sensing techniques can be performed to recognize spatial
alteration pattern as one of the standard procedures in
exploration geology, due to its speed and price (Yetkin, et.
al., 2004). Additionally, the purpose of the study is to
clarify the distribution of alteration pattern as well as
thermal anomaly in an initial stage of geothermal
exploration.
International Symposium on Earth Science and Technology 2016
INTRODUCTION
STUDY AREA
Study area in True Color Composition (RGB 4,3,2)
MATERIALS AND METHOD
Landsat 8 Bands Specification (USGS, 2016)
ANALYSIS AND RESULT
Color CompositeRed color represents vegetated
area, blue color represents the
contrasts of temperature, while the
bright (white) color represents the
area with hydrothermal alteration
zones.
RGB 5,7,10
RGB 7, 3, 5
Blue color represents vegetated
area and the brighter pixels
represents clay minerals that
indicate hydrothermal alteration
zone.
RGB 7, 5, 3
The reddish color shows iron oxide
minerals. Green color corresponds
to vegetated area. The brighter
color represents hydrothermal
alteration zone.
Band Ratio
Altered iron-oxide is reflected as
light purple color, the magenta color
represents vegetated area. The green
color represents clay minerals
distribution.
Abram Ratio RGB 6/7, 4/3, 5/6
Light purple color represents iron-
oxide minerals distributed around
the Sirung crater, the cyan color
represents the distribution of clay
minerals.
Chica-Olma Ratio RGB 6/7, 6/5, 4/2
Blue color represents clay minerals
distributed around the Sirung crater
and cyan color represents vegetated
area.
Kaufmann Ratio RGB 7/5, 4/3, 5/6
From the band ratio analysis above, the altered minerals
are distributed well around the crater and spotted in
northeast of the study area.
Principal Component AnalysisPCA for bands 2-7
Eigenvector Band 2 Band 3 Band 4 Band 5 Band 6 Band 7 Eigenvalue
PC1 0.042 0.124 0.151 0.789 0.521 0.256 21143981.278.95%
PC2 -0.307 -0.357 -0.515 0.511 -0.329 -0.379 4489626.495.71%
PC3 -0.351 -0.424 -0.406 -0.319 0.584 0.299 1076948.199.74%
PC4 -0.503 -0.281 0.454 0.086 -0.415 0.532 45859.699.91%
PC5 0.491 0.019 -0.496 0.072 -0.321 0.635 19795.199.98%
PC6 -0.536 0.773 -0.308 -0.036 -0.058 0.125 5235.5 100%
Eigenvector Band 2 Band 5 Band 6 Band 7 Eigenvalue
PC1 -0.249 -0.522 -0.815 -0.031 20429863.7 85%
PC2 -0.536 -0.576 0.544 -0.291 2950952.5 98%
PC3 0.051 -0.348 0.172 0.920 402443.1 99%
PC4 -0.805 0.523 -0.099 0.261 34856.5 100%
PCA for bands 2, 5, 6, 7
Eigenvector Band 2 Band 4 Band 5 Band 6 Eigenvalue
PC1 0.136 0.526 0.839 0.032 19556436.4 83%
PC2 0.636 0.516 -0.441 0.367 3163372.1 96%
PC3 0.518 -0.670 0.319 0.426 790412.5 99%
PC4 0.555 -0.096 0.001 -0.826 31785.7 100%
PCA for bands 2, 4, 5,6
PC4 image of bands 2,5,6,7 (H image)
H image shows the hydroxyl
minerals displayed as bright pixels
around the Sirung crater.
PC4 image of bands 2,4,5,6 (F image)
F image shows the oxide minerals
displayed as bright pixels around the
Sirung crater.
RGB H, H+F, F
Hydroxyl minerals are displayed as
light orange color in map. While
the iron oxide mineral is displayed
as light blue color. The distribution
of the iron oxide minerals spreads
around the Sirung crater with
wider distribution.
Land Surface Temperature
Based on our analysis, an area
with anomalous heat is centred
around Mount Sirung's crater.
The distribution of this
anomalous heat spreads to the
south of the crater, and to the
west along a northwest-
southeast trending lineament
Heat Anomaly Using Band 10
CONCLUSIONHydrothermal alteration mapping in the study area was
successfully carried out using composite colour and band
ratio methods. PCA transformations of bands 2, 5, 6, 7 and
bands 2, 4, 5, 6 were carried out to determine the
distribution of hydroxyl and iron oxide minerals in this
area. Based on these three methods, the distribution of
alteration minerals around Mount Sirung's crater was
determined. Iron oxide minerals had a wider distribution
than hydroxyl minerals, which were centred just around the
crater. The distribution of hydrothermal alteration
minerals corresponds well with the heat anomaly
characterised by LST methods. Based on our analysis, we
conclude that the formation of hydrothermal alteration
minerals is closely associated with anomalous heat in the
Pantar Geothermal Area.
REFERENCESAguilera, F., Layana, S., Rodriguez-Diaz, A., Gonzalez,
C., Cortes, J., & Inostroza, M. (2016).
Hydrothermal Alteration, Fumarolic Deposits and
Fluids from Lastarria Volcanic Complex: A
Multidisciplinary Study. Andean Geology, 42, pp.
166-196.
Loughlin, W. (1991). Principal Component Analysis for
Alteration Mapping. Photogrammetric Engineering
and Remote Sensing, 57, (pp. 1163-1169).
Nur Hadi, M., & Kusnadi, D. (2015). Survei Geologi dan
Geokimia Daerah Panas Bumi Pulau Pantar
Kabupaten Alor, Provinsi Nusa Tenggara Timur.
Prosiding Hasil Kegiatan Lapangan Pusat Sumber
Daya Geologi Tahun Anggaran 2015, (pp. 77-90).
Bandung.
USGS. (2016). Landsat 8 (L8) Data Users Handbook.
South Dakota.
Yetkin, E., Toprak, V., & Süzen, M. (2004). Alteration
Mapping by Remote Sensing: Application to
Hasandag – Melendiz Volcanic Complex, Central
Turkey. Geo-Imagery Bridging Continents XXth
ISPRS Congress. Istanbul.
ACKNOWLEDGEMENT
The authors would like to show their sincere gratitude to
JICA for organizing the ‘Intensive Training for Geothermal
Resource Engineers’ program. Also thank to Department of
Earth Resources Engineering of Kyushu University,
especially to Laboratory of Geothermics who have helped
in this study. Thanks to NASA which has been producing
Landsat 8 for free. The authors also thank to the MEMR of
the Republic of Indonesia for giving opportunity to
participate in this program.
Remote sensing is among the most important methods in
the early stages of a geothermal survey, especially for
mapping hydrothermal alteration. In this study,
conventional methods were applied to determine the
distribution of the hydrothermal anomaly in the Pantar
Geothermal Area, using Landsat 8 satellite images. The
distribution of hydrothermal mineral alteration around the
Mount Sirung was successfully determined by applying
colour composite, band ratio, and principal component
analysis techniques. The distribution of these
hydrothermal alteration minerals was correlated with the
thermal anomaly distribution derived from land surface
temperatures in the study area.
ABSTRACT
The image used in this study is Landsat-8 (OLI and TIRS )
that was acquired on July 9th 2016. The methods used in
this study are:
• Color Composite
• Band Ratio
• Principal Component Analysis (PCA)
• Land Surface Temperature (LST)
Landsat-8 OLI and TIRS Bands (µm) Landsat-8 OLI and TIRS Bands (µm)
30 m Coastal/Aerosol 0.435-0.451Band 1 100 m TIR-1 10.60-11.19 Band 10
30 m Blue 0.452-0.512Band 2 100 m TIR-2 11.50-12.51 Band 11
30 m Green 0.533-0.590Band 3 30 m SWIR-2 2.107-2.294Band 7
30 m Red 0.636-0.673Band 4 15 m Pan 0.503-0.676Band 8
30 m NIR 0.851-0.879Band 5 30 m Cirrus 1.363-1.384Band 9
30 m SWIR-1 1.566-1.651Band 6
The study area is located in
Pantar Geothermal Area,
Pantar Island in East Nusa
Tenggara Province. It lies
within the tectonic setting
of the Inner Banda volcanic
arc, dominated by volcanic
rocks from the still active
Mount Sirung (Nur Hadi
and Kusnadi, 2015)