tectonic implications of uplifted holocene marine...

Tectonic implications of uplifted Holocene marine terraces Tectonic implications of uplifted Holocene marine terraces in in PangasinanPangasinan and Davao Oriental, Philippinesand Davao Oriental, Philippines

NoelynnaNoelynna T. T. RamosRamosaa, Hiroyuki , Hiroyuki TsutsumiTsutsumibb, Jeffrey S. , Jeffrey S. PerezPerezb,cb,c, and Percival P. , and Percival P. BermasBermas, , Jr.Jr.dd

aaRushurgentRushurgent Working Group, National Institute of Geological Sciences, College of Science, Working Group, National Institute of Geological Sciences, College of Science,

University of the Philippines, University of the Philippines, DilimanDiliman, Quezon City 1101, Philippines, Quezon City 1101, Philippines bbDepartmentDepartment of Geophysics, Graduate School of Science, Kyoto University, Kyoto 606of Geophysics, Graduate School of Science, Kyoto University, Kyoto 606--8502, Japan8502, Japan

ccDepartmentDepartment of Science and Technology of Science and Technology -- Philippine Institute of Philippine Institute of VolcanologyVolcanology and Seismology, and Seismology,

C. P. Garcia Avenue, C. P. Garcia Avenue, DilimanDiliman, Quezon City 1104, Philippines, Quezon City 1104, Philippines ddMinesMines and Geosciences Bureau XI and Geosciences Bureau XI -- Department of Environment and Natural Resources, Department of Environment and Natural Resources,

69 69 KonsuelaKonsuela Bldg., cor. Jacinto St., Davao City 8000, PhilippinesBldg., cor. Jacinto St., Davao City 8000, Philippines

GeoConGeoCon 2011: Geology Working For A Resilient Society2011: Geology Working For A Resilient Society

CrowneCrowne Plaza Hotel, Quezon CityPlaza Hotel, Quezon City

08 December 201108 December 2011

NoelynnaNoelynna T. T. RamosRamosaa, Hiroyuki , Hiroyuki TsutsumiTsutsumibb, Jeffrey S. , Jeffrey S. PerezPerezb,cb,c, and Percival P. , and Percival P. BermasBermas, , Jr.Jr.dd

aaRushurgentRushurgent Working Group, National Institute of Geological Sciences, College of Science, Working Group, National Institute of Geological Sciences, College of Science,

University of the Philippines, University of the Philippines, DilimanDiliman, Quezon City 1101, Philippines, Quezon City 1101, Philippines bbDepartmentDepartment of Geophysics, Graduate School of Science, Kyoto University, Kyoto 606of Geophysics, Graduate School of Science, Kyoto University, Kyoto 606--8502, Japan8502, Japan

ccDepartmentDepartment of Science and Technology of Science and Technology -- Philippine Institute of Philippine Institute of VolcanologyVolcanology and Seismology, and Seismology,

C. P. Garcia Avenue, C. P. Garcia Avenue, DilimanDiliman, Quezon City 1104, Philippines, Quezon City 1104, Philippines ddMinesMines and Geosciences Bureau XI and Geosciences Bureau XI -- Department of Environment and Natural Resources, Department of Environment and Natural Resources,

69 69 KonsuelaKonsuela Bldg., cor. Jacinto St., Davao City 8000, PhilippinesBldg., cor. Jacinto St., Davao City 8000, Philippines

GeoConGeoCon 2011: Geology Working For A Resilient Society2011: Geology Working For A Resilient Society

CrowneCrowne Plaza Hotel, Quezon CityPlaza Hotel, Quezon City

08 December 201108 December 2011

Holocene coastal uplift in the western Pacific Holocene coastal uplift in the western Pacific

HT: 6 (21 m)

HT: 6 (11 m)

HT: 7 (24 m)

(80 m)

Bathymetriy: NGDC; Topography: SRTM; PFZ: Tsutsumi and Perez, 2010; Instrumental seismicity (M>6) (1897-2008): PHIVOLCS;

Historical seismicity (M>6) (1619-1894): Bautista and Oike, 2000

1897 - 2008 1619 - 1894

Seismicity in the Philippines Seismicity in the Philippines

Holocene coastal uplift in the western Pacific Holocene coastal uplift in the western Pacific

HT: 6 (21 m)

HT: 6 (11 m)

HT: 7 (24 m)

(80 m)

Objectives Objectives

To identify and systematically map Holocene marine

terraces in Pangasinan and Davao Oriental

To evaluate the seismotectonic potential of tectonic

structures (e.g. Manila trench, Philippine trench)

Western Pangasinan Western Pangasinan

Bathymetry: NGDC; Topography: NASA; GPS vectors: Rangin et al., 1999; Focal mechanisms (1976-2008): Global CMT;

Seismicity (1897-2008) and PFZ: PHIVOLCS

Terrace maps Terrace maps

Modified from Maemoku and Paladio, 1992

Holocene marine terraces Holocene marine terraces


Deformation pattern and tectonic implications Deformation pattern and tectonic implications

prehistoric earthquakes are

probably offshore

Elastic dislocation model 1: Megathrust fault Elastic dislocation model 1: Megathrust fault

Fault parameters Fault model

b-b’ c-c’

Strike (º) 0 N-S N-S

Dip angle (º) 30~50 30 40

Top depth (km) 0 0 0

Bottom depth (km) 40~70 50 60

Amount of reverse slip (m) 10~26 16 16


b-b’ c-c’


Dip angle (º) 30~50 30 40




Elastic dislocation model 1: Megathrust fault Elastic dislocation model 1: Megathrust fault


a-a’ c-c’


Dip angle (º) 30~80 30 60




Elastic dislocation model 2: Intraplate fault Elastic dislocation model 2: Intraplate fault


a-a’ c-c’


Dip angle (º) 30~80 30 60




Elastic dislocation model 2: Intraplate fault Elastic dislocation model 2: Intraplate fault

Eastern Davao Oriental Eastern Davao Oriental

Bathymetry: NGDC; Topography: NASA; GPS vectors: Rangin et al., 1999; Focal mechanisms (1976-2008): Global CMT;

Seismicity (1897-2008): PHIVOLCS; PFZ main trace: Tsutsumi and Perez (2010)


Deformation pattern Deformation pattern

Conclusions Conclusions

Pangasinan

Davao Oriental

Summary and conclusions Summary and conclusions

Pangasinan Davao Oriental

Elevation of

paleoshoreline

angle (m amsl)

TIV -- 8~12

TIII / T3 4~11 6~10

TII / T2 2~7 3~6

TI / T1 1~5 1~5

Radiocarbon

ages (cal yr BP) 6480 to 1325 8080 to 4140

Maximum uplift

rate (mm/yr)

Pleistocene ~1.3 ~1.3

Holocene ~1.7 ~1.5

Deformation

pattern

paleoshoreline angles are highest along headlands

facing the subduction zone (e.g. Manila trench,

Philippine trench)

Uplift

mechanism coseismic uplift

Earthquake

magnitude 7.7~8.5 > 7.5

Source fault offshore reverse fault (offshore reverse fault)

Thank youThank you

Kyoto University (Active Tectonics lab, S. Toda, N. Kyoto University (Active Tectonics lab, S. Toda, N. ShimobayashiShimobayashi))

PaleoLabPaleoLab, Japan, Japan

Y. Ota, A. Y. Ota, A. MeltznerMeltzner, M. Liu, , M. Liu, J.B.H.ShyuJ.B.H.Shyu, N. Litchfield, N. Litchfield

University of the Philippines (University of the Philippines (RushurgentRushurgent Working Group Working Group -- National National

Institute of Geological Sciences, Marine Science Institute)Institute of Geological Sciences, Marine Science Institute)

Philippine Institute of Volcanology and SeismologyPhilippine Institute of Volcanology and Seismology

Mines and Geosciences BureauMines and Geosciences Bureau

local government officials of local government officials of PangasinanPangasinan and Davao Oriental and Davao Oriental

provincesprovinces

tectonic implications of uplifted holocene marine...

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