Chlorophyll concentration and surface temperature changes associated with earthquakes
- 233 Downloads
The preparation process of an impending earthquake may leave fingerprints on the earth’s surface. Elastic strain in rocks, formation of micro-cracks, gas releases and other chemical or physical activities in the earth’s crust before and during earthquakes has been reported to cause rises in temperature, surface latent heat flux (SLHF), upwelling index and chlorophyll-a (Chl-a) concentration on the ground or sea surface. Changes in surface temperature can be monitored with thermal infrared sensors such as NOAA-AVHRR and microwave radiometers like AMSR-E/Aqua. SLHF data and upwelling indices are provided by National Centers for Environmental Prediction (NCEP) Reanalysis Project and Pacific Fisheries Environmental Laboratory, respectively. This study examines behaviors of the above four factors prior to the past three oceanic and coastal earthquakes occurred at the Pacific Ocean (Northern California of June 15, 2005, Central California of September 28, 2004, and December 22, 2003). We were successful in detecting pre-earthquake anomalies prior to all three earthquakes. Our detailed analysis revealed 1–5 °C rises in surface temperature in epicentral areas. Considerable anomalies in Chl-a concentration, 1–2 weeks before the day of the main earthquakes, were spotted, which are attributed to the rise in upwelling index. Time series of SLHF showed meaningful rises from 1 month to a fortnight before the earthquake events. One problem in our research was the low resolution of the data which makes the graphs that are generated from NCEP database affected by all sources of anomalies, other than seismic activities, within an about 1.8°–2.5° (200 km) area.
KeywordsEarthquake Chlorophyll Surface temperature Satellite Early information Upwelling
The SLHF data have been downloaded from NCEP site. MDOIS Chl-a and AVHRR’s SST data were also used. Upwelling indices for the Pacific Ocean have been downloaded from Pacific Fisheries Environmental Laboratory (PFEL). AMSR-E data are provided by the National Space Development Agency of Japan (NASDA). Reanalysis data are downloaded from the IRI/LDEO Climate Data Library. Here, we greatly appreciate their help. The authors are thankful to two anonymous reviewers for their useful comments and suggestions which helped us to improve the original version of the manuscript.
- Bisset WP, Schofield O, Glenn S, Cullen JJ, Miller WL, Plueddmann AJ (2001) Resolving the impacts and feedback of ocean optics on upper ocean ecology. J Oceanogr Soc 14(4):30–53Google Scholar
- Freund F, Ouzonouv D (2001) EOS Trans. AGU, Fall Meet. Suppl. Abstract 82(47)Google Scholar
- Gorny VI, Salman AG, Tronin AA, Shilin BB (1988) Outgoing IR radiation of the Earth as an indicator of seismic activity. Proc Acad Sci USSR 301(1):67–69Google Scholar
- Nosov MA (1998) Ocean surface temperature anomalies from underwater earthquakes. Volcanol Seismol J 19(3):371–376Google Scholar
- Ouzounov D, Freund F (2003) Mid-infrared emission prior to strong earthquakes analyzed by remote sensing data. Adv Space Res 33/3:268–273Google Scholar
- Saraf AK, Choudhury S (2005) Thermal Remote Sensing technique in the study of pre-earthquake thermal anomalies. J Ind Geophys Union 9(3):197–207Google Scholar
- Singh RP, Dey S, Singh VP, Cervone G, Sarkar S, Kafatos M (2004) Prediction of coastal earthquakes using surface latent heat flux retrieved from satellite data. In: Proceedings of the world congress on natural disaster mitigation. World Federation of Engineering Organization, vol 2, pp 129–134Google Scholar
- Thomas A, Brickley P, Ted Strub P (2002) Large-scale Chlorophyll variability along the eastern Pacific coastal margin. Investig Mar V.30, N.1 Sup1, Symp Valparaiso ago 2002Google Scholar
- Wang D, Deckter E, Wong T, Wielicki A (2002) Sensitivities of cloud and radiation to changes in SST over the tropical eastern Pacific: results from Cloud-resolving simulations. In: Proceedings of 25th conference on hurricanes and tropical meteorology, 29 April–3 May, 2002, San Diego, CA, USAGoogle Scholar