A new real-time tsunami detection algorithm

Real-time tsunami detection algorithms play a key role in any Tsunami Early Warning System. We have developed a new algorithm for tsunami detection based on the real-time tide removal and real-time band-pass filtering of seabed pressure recordings. The algorithm greatly increases the tsunami detection probability, shortens the detection delay and enhances detection reliability with respect to the most widely used tsunami detection algorithm, while containing the computational cost. The algorithm is designed to be used also in autonomous early warning systems with a set of input parameters and procedures which can be reconfigured in real time. We have also developed a methodology based on Monte Carlo simulations to test the tsunami detection algorithms. The algorithm performance is estimated by defining and evaluating statistical parameters, namely the detection probability, the detection delay, which are functions of the tsunami amplitude and wavelength, and the occurring rate of false alarms. Pressure data sets acquired by Bottom Pressure Recorders in different locations and environmental conditions have been used in order to consider real working scenarios in the test. We also present an application of the algorithm to the tsunami event which occurred at Haida Gwaii on 28 October 2012 using data recorded by the Bullseye underwater node of Ocean Networks Canada. The algorithm successfully ran for test purpose in year-long missions onboard abyssal observatories, deployed in the Gulf of Cadiz and in the Western Ionian Sea.

EC NEAREST project (GOCE0307110) , LIDO - EC-ESONET DM
Mission (036851) and RITMARE

Abdolali A., C. Cecioni, G. Bellotti, and J. T. Kirby (2015), Hydro-acoustic and tsunami waves generated by the 2012 HaidaGwaii earthquake:
Modeling and in situ measurements, J. Geophys. Res. Oceans, 120, 958–971, doi:10.1002/2014JC010385.
An, C., and P. L.-F. Liu (2014), Characteristics of leading tsunami waves generated in three recent tsunami events, J. Earthquake Tsunami, 8,
1440001. doi:10.1142/S1793431114400016.
Bagheri, A., S. Greenhalgh, A. Khojasteh, M. Rahimian, and R. Attarnejad (2016), Tsunami generation and associated waves in the water col-
umn and seabed due to an asymmetric earthquake motion within an anisotropic substratum, J. Geophys. Res. Oceans, 121, 7701–7715,
doi:10.1002/2016JC011944.
Beltrami, G. M. (2008), An ANN algorithm for automatic, real-time tsunami detection in deep-sea level measurements, Ocean Eng., 35,
572–587.
Beltrami, G. M., and P. De Girolamo (2006), Preannuncio di un evento di maremoto—parte 1: Identificazione in tempo reale dell’evento
(Tsunami Detection) Atti del XXX Convegno di Idraulica e Costruzioni Idrauliche—IDRA 2006. [Available at www.idra2006.it/referee/ les/
L238.pdf.]
Beltrami, G. M., and M. Di Risio (2011), Algorithms for automatic, real-time tsunami detection in wind-wave measurements. Part I: Imple-
mentation strategies and basic tests, Coastal Eng., 58, 1062–1071, doi:10.1016/j.coastaleng.2011.06.004.
Bressan, L., and S. Tinti (2011), Structure and performance of a real-time algorithm to detect tsunami or tsunami-like alert conditions based
on sea-level records analysis, Nat. Hazards Earth Syst. Sci., 11, 1499–1521.
Bressan, L., and S. Tinti (2012), Detecting the 11 March 2011 Tohoku tsunami arrival on sea-level records in the Pacific Ocean: Application
and performance of the Tsunami Early Detection Algorithm (TEDA), Nat. Hazards Earth Syst. Sci., 12, 1583–1606.
Bryant, E. (2014), Tsunami The Underrated Hazard, 3rd ed., chap. 2, Springer Int. Publ., Switzerland, doi:10.1007/978-3-319-06133-7.
Cassidy, J. F., G. C. Rogers, and R. D. Hyndman (2014), An overview of the 28 October 2012 Mw 7.7 Earthquake in Haida-Gwaii, Canada: A tsu-
namigenic thrust event along a predominantly strike-slip margin, Pure Appl. Geophys., 171(12), 3457–3465, doi:10.1007/s00024-014-0775-1.
Chierici, F., et al. (2007), An innovative tsunami detector operating in tsunami generation environment, Eos Trans. AGU, 88(52), Fall Meet.
Suppl., Abstract S53A-1031.
Chierici, F., D. Embriaco, L. Pignagnoli, L. Beranzoli, P. Favali, G. Marinaro, S. Monna, F. Bruni, F. Furlan, and F. Gasparoni (2008), An innova-
tive tsunami detector operating on a multiparameter seafloor observatory, Geophys. Res. Abstr., 10, EGU2008-A-07393, Abstract of the
contributions of the EGU General assembly Vienna, 13–18 April 2008.
Chierici, F., L. Pignagnoli, and D. Embriaco (2010), Modeling of the hydro-acoustic signal and tsunami wave generated by sea floor motion
including a porous seabed, J. Geophys. Res., 115, C03015, doi:10.1029/2009JC005522.
Chierici, F., et al. (2012), NEMO-SN1 (Western Ionian Sea, off eastern Sicily): A cabled abyssal observatory with tsunami early warning capa-
bility, in Proceedings of the International Offshore and Polar Engineering Conference 2012, edited by S. Jin et al. 130–137, International
Society of Offshore and Polar Engineers, Cupertino, Calif.
Di Risio, M., and G. M. Beltrami (2014), Algorithms for automatic, real-time tsunami detection in wind-wave measurements: Using strategies
and practical aspects, Procedia Eng., 70, 545–554, doi:10.1016/j.proeng.2014.02.060.
Favali P., et al. (2013), NEMO-SN1 abyssal cabled observatory in the Western Ionian Sea, IEEE J. Oceanic Eng., 38(2), 358/374, doi:10.1109/
JOE.2012.2224536.
Filloux, J. H. (1980), Pressure fluctuations on the open ocean floor over a broad frequency range: New program and early results, J. Phys.
Oceanogr., 10, 1959–1971.
Filloux, J. H. (1982), Tsunami recorded on the open ocean floor, J. Phys. Oceanogr., 13, 783–796.
Filloux, J. H. (1983), Pressure fluctuations on the open ocean floor of the Gulf of California: Tides, earthquakes, tsunamis, Geophys. Res. Lett.,
9, 25–28.
Foreman, M. G. G. (1977), Manual for tidal heights analysis and prediction [2004 revision], Pac. Mar. Sci. Rep. 77-10, Inst. of Ocean Sci.,
58 pp., Patricia Bay, Sidney, B. C.
Giovanetti, G., et al. (2016), Observing volcanoes from the seafloor in the Central Mediterranean Area, Remote Sens., 8(4), 298, doi:10.3390/
RS8040298.
Gonzalez, F. J., H. M. Milburn, E. N. Bernard, and J. C. Newman (1998), Deep-ocean Assessment and Reporting of Tsunamis (DART): Brief
overview and status report, in Proceedings of the International Workshop on Tsunami Disaster Mitigation, pp. 118–129, Meteorological
Agency and Science and Technology Agency, Tokyo, Japan. Gualtieri, L., E. Stutzmann, Y. Capdeville, V. Farra, A. Mangeney, and A. Morelli (2015), On the shaping factors of the secondary microseismic
wavefield, J. Geophys. Res. Solid Earth, 120, 6241–6262, doi:10.1002/2015JB012157.
Kadri, U., and T. R. Akylas (2016), On resonant triad interactions of acoustic-gravity waves, J. Fluid Mech., 788, R1, doi:10.1017/jfm.2015.721.
Kibblewhite, A. C., and K. C. Ewans (1985), Wave-wave interactions, microseisms, and infrasonic ambient noise in the ocean, J. Acoust. Soc.
Am., 78, 981–994.
Jay, D. A., and E. P. Flinchem (1999), A comparison of methods for analysis of tidal records containing multi-scale non-tidal background
energy, Cont. Shelf Res., 19, 1695–1732.
Lamb H. (1932), Hydrodynamics, Dover, New York, ISBN: 0486602567.
Madsen, P. A., D. R. Fuhrman, and H. A. Sch€ affer (2008). On the solitary wave paradigm for tsunamis, J. Geophys. Res., 113, C12012, doi:
10.1029/2008JC004932.
McGehee, D., and J. McKinney (1997), Tsunami detection and warning capability using near shore submerged pressure transducers—Case
study of the 4 October 1994 Shikotan Tsunami, in Perspectives on Tsunami Hazard Reduction. Observation, Theory and Planning, edited
by G. Hebenstreit, pp. 133–144, Springer, Netherlands.
Meinig, C., S. E. Stalin, A. I. Nakamura, F. J. Gonzalez, and H. G. Milburn (2005), Technology developments in real-time tsunami measuring,
monitoring and forecasting, in Oceans 2005 MTS/IEEE, September 18-23, Editor and Pubblisher Marine Technology Society, Washington,
D. C.
€
Menold, P. H., R. K. Pearson, and F. Allg AOwer
(1999), Online outlier detection and removal, in Proceedings of the 7th Mediterranean
Conference on Control and Automation, MED’99, Haifa, Israel, pp. 1110–1133.
Metropolis, N., and S. Ulam (1949), The Monte Carlo method, J. Am. Stat. Assoc., 44(247), 335–341, doi:10.2307/2280232.
Milburn, H. M., A .I. Nakamura, and F. J. Gonzalez (1996), Real-time tsunami reporting from deep ocean, in Proceedings of the OCEAN96
MTS/IEEE International Conference, edited by Marine Technology Society and Institute of Electrical and Electronics Engineers, pp. 390–
394, Publisher Oceans ’96 MTS/IEEE Conference Committee, Fort Lauderdale, Fla.
Mofjeld, H. O. (1997), Tsunami Detection Algorithm, Not published paper. [Available at http://nctr.pmel.noaa.gov/tda_documentation.
html.]
Monna, S., et al. (2014), Underwater geophysical monitoring for European Multidisciplinary Seafloor and water column Observatories,
J. Mar. Syst., 130, 12–30, doi:10.1016/j.jmarsys.2013.09.010.
Oliveira, T. C. A., and U. Kadri (2016), Pressure field induced in the water column by acoustic-gravity waves generated from sea bottom
motion, J. Geophys. Res. Oceans, 120, 958–971, doi:10.1002/2016JC011742.
Panizzo A., G. Bellotti, and P. De Girolamo (2002), Application of wavelet transform analysis to landslide generated waves, Coastal Eng.,
44(4), 321–338.
Panizzo A., P. De Girolamo, and A. Petaccia (2005), Forecasting impulse waves generated by subaerial landslides, J. Geophys. Res., 110,
C12025, doi:10.1029/2004JC002778.
Pawlowicz, R., B. Beardsley, and S. Lentz (2002), Classical tidal harmonic analysis including error estimates in MATLAB using T_TIDE, Com-
put. Geosci., 28, 929–937.
Pugh, D. T. (1982), A comparison of recent and historical tides and mean sea-levels of Ireland, Geophys. J. R. Astron. Soc., 71, 809–815.
Rabinovich, A., and M. Ebl e (2015), Deep-ocean measurements of tsunami waves, Pure Appl. Geophys., 172, 3281–3312, doi:10.1007/s00024-
015-1058-1.
Sanderson, K. (2008), Seismic stations could help catch tsunami waves, Nature, doi:10.1038/news.2008.618.
Tadepalli, S., and C. E. Synolakis (1996), Model for the leading waves of tsunamis, Phys. Rev. Lett., 77, 2141–2145.
Tanioka, Y., L. Ruff, and K. Satake (1995), The Great Kurile earthquake of October 4, 1994 tore and slab, Geophys. Res. Lett., 22(13),
1661–1664.
Tian, Y., and M. H. Ritzwoller (2015), Directionality of ambient noise on the Juan de Fuca plate: Implications for source locations of the
primary and secondary microseisms, Geophys. J. Int., 201(1), 429–443, doi:10.1093/gji/ggv024.
Titov, V. V., A. B. Rabinovich, H. O. Mofjeld, R. E. Thomson, and F. J. Gonzalez (2005), The global reach of the 26 December 2004 Sumatra
Tsunami, Science, 309(5743), 2045–2048.
Tolkova, E. (2010), EOF analysis of a time series with application to tsunami detection, Dyn. Atmos. Oceans, 50(1), 35–54.
Traer, J., and P. Gerstoft (2014), A unified theory of microseisms and hum, J. Geophys. Res. Solid Earth, 119, 3317–3339, doi:10.1002/
2013JB010504.
Wah, B. W., and M. Qian (2002), Constrained formulations and algorithms for stock-price predictions using recurrent FIR neural networks,
in Proceedings of the 18th National Conference on artificial intelligence (AAAI-2002), Edmonton, Alberta, Canada edited by R. Dechter,
M. Kearns, and R. Sutton, The AAAI Press, Menlo Park, Calif.
Zielinski, A., and N. K. Saxena (1983), Tsunami detectability using open-ocean bottom pressure fluctuations, IEEE J. Oceanic Eng., 8(4),
272–280.