Surface Anomalies Prior to Earthquakes Habibeh Valizadeh, Shattri B. - PDF document

16-05-2013 Surface Anomalies Prior to Earthquakes Habibeh Valizadeh, Shattri B. Mansor Husaini Omar and Farid Azad Department of Civil Engineering Universiti Putra Malaysia Serdang, Selangor Malaysia shattri@eng.upm.edu.my Introduction Introduction Recently, new theories on underground geophysical and geochemical interactions occur during preparation stages of earthquakes and the resultant measurable variations have been put into test and some warning factors were suggested as earthquake precursors. In case of oceanic and coastal earthquakes, with thinner crust, these pre-earthquake activities may be detected through secondary oceanic and atmospheric phenomenon. Earthquake Precursor ≠ ≠ ≠ ≠ Earthquake Prediction 1

16-05-2013 Earthquakes? Earthquakes? Are they really predictable? •Vibrations in the earth are caused by sudden release of energy. •This energy is produced somewhere within the crust. •Its formation and existence produce phenomena under, on and above the ground. •Satellite-based measurements and ground observation networks can be specialized to monitor the earthquakes-related changes. Earthquake Precursors Earthquake Precursors • Temperature anomalies • SLHF (higher atmosphere-surface energy exchange) • Chl-a concentration • Radon gas emission • Crust Deformations • Strange cloud formation • Seismic pattern 2

16-05-2013 Frequency and distribution ( 1973-2012) Frequency and distribution ( 1973-2012) Earthquake Precursors Earthquake Precursors Short Term Long Term Hours/Days/Weeks Months/Years/Decade Seismology Earthquake Remote Sensing event In-situ measurement Our concern is: Earthquake precursors prior to the event Remote Sensing (Hours/Days/Weeks) 3

16-05-2013 Monitoring the Precursors � Free available remote sensing data covering large scales allow Possibilities monitoring the earth’s surface. � Data providers produce high-quality and trustable data using in-situ measurement networks and validation models. � Attenuation of received signals. � Significant seasonal and natural changes on the surface masking the earthquake-related anomalies. Problems � Anomalies due to human activities. � Limited knowledge on the local fault regime; earthquake formation site and places of vibration. � Low resolution remote sensing data and insufficient number of ground stations. Workflow Workflow Identifying the available maps, remote sensing data, reanalysis information, fault distribution maps and geological setting • Earthquake characteristics Characterization • Minor shake mapping Area Seismographs Space- Historical Fault maps and • Seismic gaps based data shakes tectonic information • Statistical analysis • Long-term prediction Statistical analysis, visual inspection, abnormality Descriptive detection, mapping the spatial distribution of Analysis variations Expected results Recognizing of Determining Detection of the concurrent precursors, the Suspected the suitable determination of active faulting Area for future precursors quakes Assessing the extents of the earthquake area and the possibility of monitoring seismic activity from Analytical Analysis satellite data for the case study area Evaluation of the available earthquake preparation theories by concurrencies of RS-based precursors and seismic records 4

16-05-2013 Data Data Surface Latent Heat Flux from NCEP Surface Temperature from ASTER, AVHRR or AMSR-E Data Chlorophyll-a from MODIS Upwelling Indices from PFEL NCEP: National Center for Environmental Prediction ASTER: Advanced Spaceborn Thermal Emission and Reflection Radiometer AVHRR: Advanced Very High Resolusion Radiometer AMSR: Advanced Microwave Scaning Radiometer MODIS: Moderate Resolution Imaging Spectrodiometer PFEL: Pacific Fisheries Environmental Laboratory Oceanic Case Studies 10 5

16-05-2013 Earthquake of California 2005 20 2005 1994-2003 Sigma 2 Sigma Time series of thermal 18 anomalies at the epicenter SST deg.c of the California earthquake 16 showing high values a 14 month before the main event. dashed line is the 10- 12 year average of SST for the 10 region. 1-May 16-May 31-May 15-Jun 30-Jun 15-Jul 30-Jul 14-Aug 29-Aug 140 Temporal variation in SLHF 2005 120 Surface Heat Flux (w.m-2) 2000-2004 of the California earthquake 100 covering the epicenter pixel 80 showing increase in some 60 occasions prior to the main 40 event; dashed line is the 5- 20 last-year average of SLHF 0 for the region. 1-May 16-May 31-May 15-Jun 30-Jun 15-Jul 30-Jul 14-Aug 29-Aug 11 Changes in SLHF Spatio-temporal variation in SLHF prior and after the main event of the Northern California earthquake. 12 6

16-05-2013 SST Anomalies 1 Jun 2 Jun 3 Jun 4 Jun 5 Jun 6 Jun 7 Jun 8 Jun 9 Jun 10 Jun 11 Jun 12 Jun 13 Jun 14 Jun 15 Jun 16 Jun 17 Jun 18 Jun Chl- a concentration in the ocean are intimately linked with the SST. Sudden changes in Chl- a distribution arises from sudden changes of sea thermal structure. 13 Variation of Chl-a 1 Jun 2 Jun 3 Jun 4 Jun 5 Jun 6 Jun 7 Jun 9 Jun 10 Jun 11 Jun 12 Jun 13 Jun 15 Jun 14 Jun 16 Jun 18 Jun 14 7

16-05-2013 Upwelling Index � Two major factors which cause rising in Chl- a concentration are ocean upwelling and sea surface temperature both of which are pre seismic indicators. 600 Daily averaged upwelling Upwelling Index (m3/s/100m) 400 index for Northern California earthquake 200 showing maximum rise 0 some days prior to the -200 main event; dashed line is -400 the 10-year average of 2005 1995-2004 upwelling index for the -600 1-May 16-May 31-May 15-Jun 30-Jun 15-Jul 30-Jul 14-Aug 29-Aug region. 5 2005 2006-2011 8-day averaged Chl-a for 4 Northern California Chl 8d Composite earthquake showing some 3 high Chl- a matched the 2 upwelling in terms of location and time; dashed line is the 6- 1 year average of Chl-a for the 0 region. 1-May 16-May 31-May 15-Jun 30-Jun 15-Jul 30-Jul 14-Aug 29-Aug 15 Earthquake of California 2004 100 35 2004 2004 1994-2003 Sigma 2 Sigma Surface Temperature deg.c Surface Heat Flux (w.m-2) 80 30 60 25 20 40 15 20 10 0 1-Aug 16-Aug 31-Aug 15-Sep 30-Sep 15-Oct 30-Oct 1-Aug 16-Aug 31-Aug 15-Sep 30-Sep 15-Oct 30-Oct The anomalous SLHF values before and Time series of surface temperature; shows during the earthquake of September 28, 2004; several anomalies during the preparation Red bar indicates the day of the main event. stage and sudden fall after the main event. 300 2004 1994-2003 Sigma Upwelling Index (m3/s/100m) 250 200 Daily averaged 150 upwelling index, 100 showing rises 50 before the main event. 0 -50 -100 16 1-Aug 16-Aug 31-Aug 15-Sep 30-Sep 15-Oct 30-Oct 8

16-05-2013 Variation of Chl-a 2 Sep 5 Sep 8 Sep 14 Sep 20 Sep 21 Sep 22 Sep 28 Sep 29 Sep 1 Oct 4 Oct 7 Oct Temporal distribution of Chl-a concentration ; the increasing trend to the day of the event and 17 general decrease in the area afterwards is obvious. Earthquake of California 2003 200 18 2003 1994-2003 2003 1998-2002 Sigma 2 Sigma Surface Temperature deg.c Surface Heat Flux (w.m-2) 160 17 16 120 15 80 14 40 13 0 1-Nov 16-Nov 1-Dec 16-Dec 31-Dec 15-Jan 30-Jan 1-Nov 16-Nov 1-Dec 16-Dec 31-Dec 15-Jan 30-Jan The SST and SLHF time series of the epicentral oceanic water of the earthquake of December 22, 2003 generally higher before the earthquake. The effect of aftershocks during the second half of December is also shown. 300 1.8 2003 2004-2006 Sigma 2 Sigma 200 1.6 Upwelling Index (m3/s/100m) 100 Chl-a 8d Composite 1.4 0 1.2 -100 1 -200 0.8 -300 0.6 2003 -400 0.4 1993- -500 0.2 2002 -600 0 1-Nov 16-Nov 1-Dec 16-Dec 31-Dec 15-Jan 30-Jan 1-Nov 16-Nov 1-Dec 16-Dec 31-Dec 15-Jan 30-Jan Daily averaged upwelling index and 8-day composite Chlorophyll-a time series, showing anomalies in some occasions from one month before the main event followed by a sudden downwelling and Chl-a 1 decrease immediately after that. 8 9

16-05-2013 Thermal and Heat Thermal and Heat 100 2004 F LH = LvCeUa (qs − qa) Surface Heat Flux (w.m-2) 80 1999-2003 FLH: Surface evaporation 60 Lv: Latent heat of condensation Ce: Surface exchange coefficient for moisture 40 Ua: Surface wind speed, Qs: Saturated specific humidity at ocean surface 20 Qa: Air specific humidity at 2 m above the surface . 0 1-Aug 16-Aug 31-Aug 15-Sep 30-Sep 15-Oct 30-Oct 35 Surface Temperature deg.c 30 25 Ts: LST ε : Surface emissivity 20 γ and δ : two parameters dependent on the 2004 1994-2003 Planck’s function 15 ψ 1, ψ 2, and ψ 3 : Referred to as atmospheric Sigma 2 Sigma functions (AFs) 10 1-Aug 16-Aug 31-Aug 15-Sep 30-Sep 15-Oct 30-Oct Increased Chl-a on ocean surface Increased Chl-a on ocean surface 10

16-05-2013 Chl-a & Upwelling Chl-a & Upwelling 1.8 10-Yr Average Sigma 2 Sigma 1.6 Chl-a 8d Composite 1.4 1.2 1 0.8 0.6 0.4 0.2 0 1-Nov 16-Nov 1-Dec 16-Dec 31-Dec 15-Jan 30-Jan Upwelling Index (m3/s/100m) 200 0 -200 -400 -600 1-Nov 16-Nov 1-Dec 16-Dec 31-Dec 15-Jan 30-Jan Increased SLHF & active faults Increased SLHF & active faults zones zones 250 2008 2000-2007 Sigma 2 Sigma 200 SLHF (W/m2) 150 100 50 0 1-Jan 16-Jan 31-Jan 15-Feb 1-Mar 16-Mar 31-Mar 11