發生於山區的天然災害已是一個不可避免的問題，而這些災害時常發生在惡劣的氣候狀況下或是人類難以到達的地方。因此，為了瞭解這些災害的特性，需要藉由不同類型的儀器去幫助我們進行偵測和量測。本研究使用不同的地聲感測器去偵測土石流、落石、地震等不同震源所造成的地表震動。
庭雁鳥地震儀(Yardbird seismometer)是一個由實驗室自製的海底地震儀所改裝而成的儀器，其偵測頻寬為0.3–120 Hz，可用於偵測土石流所產生的低頻訊號(< 10 Hz)。庭雁鳥地震儀對於偵測地動訊號的能力已透過落石試驗進行驗證，其效果比傳統的地聲感測器(geophone)來得好。於2012年9月，我們將庭雁鳥地震儀架設於南投縣信義鄉神木村愛玉子溪，並依序於2013和2014年記錄到兩場區域地震、兩場遠震和三場土石流事件。地震儀所量測到的區域地震與發生於四川雅安的遠震(距離測站約1800公里)，地表振動頻率範圍分別為0.3–30 Hz和<1 Hz。庭雁鳥地震儀更記錄到土石流能產生低至2 Hz的低頻地動訊號。透過攝影機的影像也發現此低頻訊號是因為土石流波湧挾帶巨大礫石所造成的。因為低頻訊號於地表傳遞時具有較慢的衰減率，使得庭雁鳥地震儀能在土石流到達測站前，提早3分40秒就偵測到土石流的訊號。
然而庭雁鳥地震儀並非商業化的儀器且已經停產，因此我們引進新型的地聲感測器 – Raspberry Shake 3D (RS3D)來偵測由土石流或落石所產生的地表震動，其偵測頻寬為0.5–40 Hz。被RS3D所記錄的震動訊號也會與傳統所用的地聲感測器(量測頻寬為5–175 Hz)所測得的結果比較。試驗結果顯示，RS3D可量測到傳統地聲感測器無法量測到的5 Hz以下的地表震動訊號。此外，試驗期間RS3D也記錄到一場偶發的區域地震的地動訊號。證明此種新型地聲感測器RS3D在監測區域地表震動訊號的表現上，已突破傳統地聲感測器(geophone)的限制。
最後，我們應用震源強度定位方法(ASL method)去定位落石及土石流。透過小規模落石和土石流的試驗，測試震源強度定位方法在針對區域地表震動訊號的定位能力。對於震源強度定位方法中的網格搜尋(grid search)，我們討論四種不同的網格數(100、50、25和10公分)以便找出對於區域監測和計算最有效率也最合適的方式。在考慮到台灣地質條件下，我們建議使用25公分的網格搜尋即可。本研究也發現，運用震源強度定位方法所產生的定位結果會被地聲感測器所記錄到的地表震動訊號強度所影響。因此，雖然震源強度定位方法能有效定位塊體運動的點位，在計算前的參數選用上應更仔細小心，以得到最佳的定位結果。

Natural disasters occurred in mountain areas have become an inevitable problem and are usually happened under severe weather condition or at the place that people hard to get. Therefore, we need to rely on various measuring instruments to help us detect and monitor. This work used different type of ground vibration sensors to detect the ground vibration signals generated by various sources, such as debris flows, rockfalls, earthquakes, and so on.
A lab-fabricated ocean bottom seismometer (Yardbird seismometer) with detection frequency range of 0.3 – 120 Hz was modified and deployed terrestrially to detect low-frequency (< 10 Hz) ground vibrations produced by debris flows. Its seismic ground motion detection ability was investigated by comparing its measurements of seismic signals produce by rockfalls with those of a geophone. After the deployment on field in September 2012, Yardbird seismometer recorded two local earthquakes, two teleseisms, and three debris flow events in 2013 and 2014. The seismic signals frequencies of the local earthquakes and teleseisms (both approximately 1800 km apart) were 0.3–30 Hz and < 1 Hz, respectively. Moreover, seismometer measurements revealed that seismic signals generated by debris flows can have minimum frequencies as low as 2 Hz. Time-matched CCD camera revealed that debris flow surge fronts with larger rocks have lower minimum frequencies. Since low-frequency seismic waves have lower spatial decay rates, the Yardbird seismometer was able to detect one debris flow event approximately 3 min 40 s before it arrived.
However, Yardbird seismometer was not a commercial instrument and no longer being manufactured. We introduced a state-to-art geophone – the Raspberry Shake 3D (RS3D), with a measuring frequency of 0.5–40 Hz to detect the ground vibration signals generated by debris flows and rockfalls. Recorded signals were compared with those obtained using a conventional geophone with a measuring frequency of 5–175 Hz. The test results revealed that the RS3D can detect ground vibration signals with frequencies lower than 5 Hz, which is beyond the capability of the conventional geophone. Furthermore, during the field test, the RS3D detected ground tremors from occasional local earthquake. This further demonstrated the capability of the RS3D for monitoring ground vibrations in its surrounding region.
At the end, we applied Amplitude Source Location (ASL) method to locate the rockfalls and debris flows by detecting the generated seismic signals using an array of RS3D. The small scale rockfall and debris flow experiment were conducted to test the ability of ASL method on locating rockfalls and debris flows. For grid search in ASL method, we discussed four different trial steps (100, 50, 25, 10 cm) to find out the most efficient and suitable way for regional monitoring and calculation. We suggested that when considering the geological condition in Taiwan, a grid size of 25 cm × 25 cm is fine enough for locating local slope disasters in mountain areas. Moreover, this study indicated that the localization results of ASL method could be affected by the seismic magnitude received by ground vibration sensor. Although ASL method has the ability on locating mass movements, the parameters that used by it should be under stricter consideration for better localization results.

1. Aki, K., Richards, P.G. Quantitative seismology. Vol.1 and 2, 2nd edn. W. H. Freeman and Company, San Francisco. 2002.
2. Allstadt, K. Extracting source characteristics and dynamics of the August 2010 Mount Meager landslide from broadband seismograms. J. Geophys. Res-Earth Surface. 118, 1472-1490, 2013.
3. Arattano, M. On the use of seismic detectors as monitoring and warning systems for debris flows. Nat. Hazards. 20, 197-213, 1999.
4. Arattano, M. On debris flow front evolution along a torrent. Phys. Chem. Earth Part B Hydrol. Ocean. Atmos. 25, 733-740, 2000.
5. Arattano, M., Marchi, L. Measurements of debris flow velocity through cross-correlation of instrumentation data. Nat. Hazards Earth Syst. Sci. 5, 137-142, 2005.
6. Arattano, M., Marchi, L. Systems and sensors for debris-flow monitoring and warning. Sensor, 8, 2436-2452, 2008.
7. Arattano, M., Marchi, L., Cavalli, M. Analysis of debris-flow recordings in an instrumented basin: Confirmations and new findings. Nat. Hazards Earth Syst. Sci. 12, 679-686, 2012.
8. Arattano, M., Moia, F. Monitoring the propagation of a debris flow along a torrent. Hydrol. Sci. J. 44, 811-823, 1999.
9. Arámbula-Mendoza, R., Valdés-González, C., Varley, N., Juarez-Garcia, B., Alonso-Rivera, P., Hernánadez-Joffre, V. Observation of vulcanian explosions with seismic and acoustic data at Popocatepetl volcano, Mexico. In Complex Monitoring of Volcanic Activity: Methods and Results; Zobin, V.M., Ed.; Nova: New York, NY, USA. pp. 13-33, 2013.
10. Bänziger, R., Burch, H. Acoustic sensors (hydrophones) as indicators for bed load transport in a mountain torrent. In Hydrology in Mountainous Regions, 1-Hydrological Measurements, the Water Cycle; IAHS Publication: Wallingford, UK; Volume 193, pp. 207-214, 1990.
11. Battaglia, J., Aki, K. Location of seismic events and eruptive fissures on the Piton de la Fournaise volcano using seismic amplitudes. J. Geophys. Res-Solid. 108, 2003.
12. Belli, G., Walter, F., McArdell, B., Gheri, D., Marchetti, E. Infrasound and seismic analysis of debris-flow events at Illgraben (Switzerland): Relating signals features to flow parameters and to the seismo-acoustic mechanism. J. Geophys. Res. Earth Surf. 127, e2021JF006576, 2022.
13. Berti, M., Genevois, R., LaHusen, R., Simoni, A., Tecca, P.R. Debris flow monitoring in the Acquabona watershed on the Dolomites (Italian Alps). Phys. Chem. Earth Part B Hydrol. Ocean. Atmos. 25, 707-715, 2000.
14. Bolt, B.A. Nuclear explosions and earthquakes, 1976.
15. Bottelin, P., Jongmans, D., Daudon, D., Mathy, A., Helmstetter, A., Bonilla-Sierra, V., Cadet, H., Amitrano, D., Richefeu, V., Lorier, L., Baillet, L., Villard, P., Donzé, F. Seismic and mechanical studies of the artificially triggered rockfall at Mount Néron (French Alps, December 2011). Nat. Hazards Earth Sys. Sci. 14, 3175-3193, 2014.
16. Burtin, A., Bollinger, L., Vergne, J., Cattin, R., Nabelek, J.L. Spectral analysis of seismic noise induced by rivers: A new tool to monitor spatiotemporal changes in stream hydrodynamics. J. Geophys. Res. Solid Earth. 113, B05301, 2008.
17. Burtin, A., Cattin, R., Bollinger, L., Vergne, J., Steer, P., Robert, A., Findling, N., Tiberi, C. Towards the hydrologic and bed load monitoring form high-frequency seismic noise in a braided river: The “torrent de St Pierre”, French Alps. J. Hydrol. 408, 43-53, 2011.
18. Chang, J.M., Chao, W.A., Chen, H., Kuo, Y.T., Yang, C.M. Locating the rock slope failures along highways and understanding their physical process using seismic signals. Earth Surface Dynamics, 9, 505-517, 2021.
19. Chao, W.A., Wu, Y.M., Zhao, L., Chen, H., Chen, Y.G., Chang, J.M., Lin, C.M. A first near real-time seismology-based landquake monitoring system. Scientific Reports, 7:43510, 2017.
20. Chen, C.H., Chao, W.A., Wu, Y.M., Zhao, L., Chen, Y.G., Ho, W.Y., Lin, T.L., Kuo, K.H., Zhang R.M. A seismological study of landquake using a real-time broadband seismic network. Geophysical Journal International, 194, 885-898, 2013.
21. Chen, H.Y. Investigation of River Seismic Signal Induced by Dam Break Triggering Sediment Transport and Water Flow. Master Thesis, National Chung Hsing University, Taiwan, 2016. (In Chinese)
22. Chen, H.-Y., Huang, C.-J., Chen, S.-C., Chao, W.-A., Yang, C.-M. Application of Raspberry Shake 3D geophone for monitoring slope disasters. J. Chin. Soil Water Conserv. 53(1), 139-145, 2022. (In Chinese)
23. Chen, S.C., An, H.P., Hsu, T.Y, Wang, C. High precision and adjusted discharge sediment, The experimental station in Landao Creek, Huisun Forest. J. Chin. Soil Water Conserv. 46(1), 1-6, 2015. (In Chinese)
24. Chou, H.T., Cheung, Y.L., Zhang, S. Calibration of infrasound monitoring system and acoustic characteristics of debris-flow movement by field studies. In Debris-Flow Hazards Mitigation: Mechanics, Prediction, and Assessment; Chen, C.-L., Major, J.J., Eds.; Millpress: Rotterdam, The Netherlands; pp. 571-580, 2007.
25. Cook, K.L., Dietze, M. Seismic Advances in Process Geomorphology. Annu. Rev. Earth Planet. Sci. 50, 183-204, 2022.
26. Cook, K.L., Rekapalli, R., Dietze, M., Pilz, M., Cesca, S., Purnachandra Rao, N., Srinagesh, D., Paul, H., Metz, M., Mandal, P., et al. Detection and potential early warning of catastrophic flow events with regional seismic networks. Sciences. 374, 87-92, 2021.
27. Dammeier, F., Moore, J.R., Haslinger, F., Loew, S. Characterization of alpine rockslides using statistical analysis of seismic signals. J. Geophys. Res-Earth. 116, F04024, 2011.
28. Deparis, J., Jongmans, D., Cotton, F., Baillet, L., Thouvenot, F., Hantz, D. Analysis of rock-fall and rock-fall avalanche seismograms in the French Alps. B. Seismol. Sol. Am. 98, 1781-1796, 2008.
29. De Haas, T., Åberg, A.S., Walter, F., Zhang, Z. Deciphering seismic and normal-force fluctuation signatures of debris flows: An experimental assessment of effects of flow composition and dynamics. Earth Surf. Process. Landf. 46, 2195-2210, 2021.
30. Feng, Z. The seismic signatures of the 2009 Shiaolin landslide in Taiwan. Nat. Hazards Earth Syst. Sci. 11, 1559-1569, 2011.
31. Fuchs, F., Lenhardt, W., Bokelmann, G. T., the AlpArray Working Group. Seismic detection of rockslides at regional scale: examples from the Eastern Alps and feasibility of kurtosis-based event location. Earth Surf. Dynam. 6, 955-970, 2018.
32. Galgaro, A., Tecca, P.R., Genevois, R., Deganutti, A.M. Acoustic module of the Acquabona (Italy) debris flow monitoring system. Natural Hazards and Earth System Sciences, 5(2), 211-215, 2005.
33. Gracchi, T., Lotti, A., Saccorotti, G., Lombardi, L., Nocentini, M., Mugnai, F., Gigli, G., Barla, N., Giorgetti, A., Antolini, F., Fiaschi, A., Matassoni, L., Casagli, N. A method for locating rockfall impacts using signals recorded by a microseismic network. Geoenvironmental Disaster. 4:26, 2017.
34. Guinai, M., Tapia, M., Pérez-Guillén, C., Surñach, E., Roig, P., Khazaradz, G., Torné, M., Royán, M.J., Echeverria, A. Remote sensing and seismic data integration for the characterization of a rock slide and an artificially triggered rock fall. Eng. Geol. 257, 105-113, 2019.
35. Hibert, C., Mangeney, A., Grandjean, G., Shapiro, N.M. Slope instabilities in Dolomieu crater, Réunion Island: From seismic signals to rockfall characteristics. J. Geophys. Res. 116, F04032, 2011.
36. Hibert, C., Mangeney, A., Grandjean, G., Baillard, C., Rivet, D., Shapiro, N.M., Satriano, C., Maggi, A., Boissire, P., Ferrazzini, V., Crawford, W. Automated identification location, and volume estimation of rockfalls at Piton de la Fournaise volcano. J. Geophys. Res-Earth Surf. 119, 1082-1105, 2014.
37. Hibert, E., Malet, J.-P., Bourrier, F., Provost, F., Berger, F., Bornemann, P., Tardif, P., Mermin, E. Single-block rockfall dynamics inferred from seismic signal analysis. Earth Surf. Dynam. 5, 283-292, 2017.
38. Huang, C.-J., Chu, C.-R., Tien, T.-M., Yin, H.-Y., Chen, P.-S. Calibration and deployment of a fiber-optic sensing system for monitoring debris flows. Sensors. 12, 5835-5849, 2012.
39. Huang, C.-J., Shieh, C.-L., Yin, H.-Y. Laboratory study of the underground sound generated by debris flows. J. Geophys. Res. Earth Surf. 109, F01008, 2004.
40. Huang, C.-J., Yeh, C.-H., Chen, C.-Y., Chang, S.-T. Ground vibrations and airborne sounds generated by motion of rock in a river bed. Nat. Hazards Earth Syst. Sci. 8, 1139-1147, 2008.
41. Huang, C.-J., Yeh, C.-H., Yin, H.-Y., and Wang, C.-L. Monitoring the underground sound of debris flows using geophones. J. Chin. Soil Water Conserv. 36(1), 39-53, 2005. (In Chinese)
42. Huang, C.-J., Yin, H.-Y., Chen, C.-Y., Yeh, C.-H., Wang, C.-L. Ground vibrations produced by rock motions and debris flows. J. Geophys. Res. Earth Surf. 112, F02014, 2007.
43. Hürlimann, M., Rickenmann, D., Graf, C. Field and monitoring data of debris-flow events in the Swiss Alps. Can. Geotech. J. 40, 161-175, 2003.
44. Itakura, Y., Inaba, H., Sawada, T. A debris-flow monitoring devices and methods bibliography. Nat. Hazards. Earth Syst. Sci. 5, 971-977, 2005.
45. Itakura, Y., Koga, Y., Takahashi, J.I., and Nowa, Y. Acoustic detection sensor for debris flow. In Debris-Flow Hazards Mitigation: Mechanics, Prediction, and Assessment. Proc., Proceedings of the First International Conference, Am. Soc. Of Civ. Eng. 747-756, 1997.
46. Iverson, R.M. The physics of debris flows. Rev. Geophys. 35, 245-296, 1997.
47. Jan, C.D., Lee, M.H. A debris-flow rainfall-based warning model. J. Chin. Soil Water Conserv. 35(3), 275-285, 2004. (In Chinese)
48. Jan, C.D., Lee, M.H., Huang, T.H. Effect of rainfall on debris flows in Taiwan. In Proceedings of the International Conference on Slope Engineering, Hong Kong, China; Volume 2, pp 741-751, 8-10 December 2003.
49. Johnson, A.M., Rodine, J.R. Debris flows. In Slope Instability; Brunsden, D., Ed.; John Wiley & Sons Ltd.: Hoboken, NJ, USA, pp.257-361, 1984.
50. Jones, G.A., Kulessa, B., Doyle, S.H., Dow, C.F., Hubbard, A. An automated approach to the location of icequakes using seismic waveform amplitudes. Ann. Glacial. 54, 1-9, 2013.
51. Kogelnig, A., Hübl, J., Suriñach, E., Vilajosana, I., McArdell, B.W. Infrasound produced by debris flow: Propagation and frequency content evolution. Nat. Hazards. 70, 1713-1733, 2014.
52. Kuehnert, J., Mangney, A., Capedeville, Y., Vilotte, J.P., Stutzmann, E., Chaljub, E., Aissaoui, E., Boissier, P., Brunet, C., Kowalski, P., Lauret, F. Locating rockfalls using inter-station ratios of seismic energy at Dolomieu crater, Piton de la Fournaise volcano. J. Geophys. Res-Earth Surface. 2021.
53. Kumagai, H.P., Palacio, M., Maeda, T., Castillo, D., Nakano, M. Seismic tracking of lahars using tremor signals. J. Volcanol. Geotherm. Res. 183, 112-121, 2009.
54. Lacroix, P., Helmstetter, A. Location of seismic signals associated with microearthquakes and rockfalls on the Séchilienne landslide, French alps. B. Seismol. Soc. Am. 101, 341-353, 2011.
55. Lai, V.H., Tsai, V.C., Lamb, M.P., Ulizio, T.P., Beer, A.R. The seismic signature of debris flows: Flow mechanics and early warning at Montecito, California. Geophys. Res. Lett. 45, 5528-5535, 2018.
56. Lavigne, F., Thouret, J.C., Voight, B., Suwa, H., Sumaryono, A. Lahars at Merapi volcano, Central Java: and overview. Journal of Volcanology and Geothermal Research. 100, 423-456, 2000.
57. Malvino, A., Bates, D.J. Electronic Principles, 7th Eds.; The McGraw-Hill Companies, Inc.: New York, NY, USA, 2007.
58. Manconi, A., Coviello, V., Galletti, M., Seifert, R. Short communication: monitoring rockfalls with the Raspberry Shake. Earth Surf. Dynam. 6, 1219-1227, 2018.
59. Marchi, L., Arattano, M., Deganutti, A. Ten years of debris-flow monitoring in the Moscardo Torrent (Italian Alps). Geomorphology. 46, 1-17, 2002.
60. Marchetti, E., Walter, F., Barfucci, G., Genco, R., Wenner, M., Ripepe, M., McArdell, B., Price, C. Infrasound array analysis of debris flow activity and implication for early warning. J. Geophys. Res. Earth Surf. 124, 567-587, 2019.
61. Matoza, R.S., Arciniega-Ceballos, A., Sanderson, R.W., Mendo-Pérez, G., Rosado-Fuentes, A., Chouet, B.A. High-broadband seismoacoustic signature of vulcanian explosions at Popocatepetl volcano, Mexico. Geophys. Res. Lett. 46, 148-157, 2019.
62. Ogiso, M., Yomogida, K. Estimation of locations and migration of debris flows on Izu-Oshima Island, Japan, on 16 October 2013 by the distribution of high frequency seismic amplitudes. J. Volcanol. Geotherm. Res. 298, 15-26, 2015.
63. Okuda, S., Okunishi, K., Suwa, H. Observation of debris flow at Kamikamihori Valley of Mt. Yakedade. In Excursion Guidebook, Proceedings of the 3rd Meeting of IGU commission on Field Experiment in Geomorphology, Kyoto, Japan, 24-30 August 1980; Disaster Prevention Research Institute: Kyoto, Japan. pp. 127-130, 1980.
64. Pierson, T.C. Flow behavior of channelized debris flows, Mount St. Helens, Washington. In Hillslope Processes: Binghamton Geomorphology Symposium 16; Taylor & Francis Group: London, UK. pp. 269-296, 1986.
65. Richie, R.M. Evaluation of rockfalls and its control. Highways Res. 17, 14-28, 1963.
66. Roberts, P.M. A versatile equalization circuit for increasing seismometer velocity response below the natural frequency. Bull. Seismol. Soc. Am. 79, 1607-1617, 1989.
67. Röösli, C., Walter, F., Husen, S., Andrews, L.C., Lüthi, M.P., Catania, G.A., Kissling, E. Sustained seismic tremors and icequakes detected in the ablation zone of the Greenland ice sheet. J. Glaciol. 60, 563-575, 2014.
68. Saló, L., Corominas, J., Lantada, N., Matas, G., Prades, A., Ruiz-Carulla, R. Seismic energy analysis as generated by impact and fragmentation of single-block experimental rockfalls. J. Geophys. Res. Earth Surf. 123, 1450-1478, 2018.
69. Shannon, C.E. Communication in the Presence of Noise. Proc IRE. 37, 10-21, 1949.
70. Schimmel, A., Coviello, V., Comiti, F. Debris flow velocity and volume estimations based on seismic data. Nat. Hazards Earth Syst. Sci. 22, 1955-1968, 2022.
71. Schimmel, A., Hübl, J. Automatic detection of debris flows and debris floods based on a combination of infrasound and seismic signals. Landslides. 13, 1181-1196, 2016.
72. Schimmel, A., Hübl, J., McArdell, B.W., Walter, F. Automatic identification of alpine mass movements by a combination of seismic and infrasound sensors. Sensors. 18, 1658, 2018.
73. Schöpa, A., Chao, W.A., Lipovsky, B.P., Hovius, N., White, R., Green, R.G., Turowski, J.M. Dynamics of the Askjacaldera July 2014 landslide, Iceland, from seismic signal analysis: precursor, motion and aftermath. Earth Surf. Dynam. 6, 467-485, 2018.
74. Shearer, P.M. Introduction to Seismology; Cambridge University Press: Cambridge, UK, 1999.
75. Soil and Water Conservation Handbook, Soil and Water Conservation Bureau, Council of Agriculture, Executive Yuan, 2017. (In Chinese)
76. Stutzmann, E., Roult, G., Astiz, L. Geoscope station noise levels. Bull. Seismol. Soc. Am. 90, 690-701, 2000.
77. Suriñach, E., Vilajosana, I., Khazaradze, G., Biescas, B., Furdada, G., Vilaplana, J.M. Seismic detection and characterization of landslides and other mass movements. Nat. Hazards Earth Syst. Sci. 5, 791-798, 2005.
78. Takahashi, T. Debris flow. In IAHR Monograph; AA Balkma Publishers: Rotterdam, The Netherlands, 1991.
79. Toksöz, M.M., and Johnson, D.H. Seismic wave attenuation. Society of Exploration Geophysics, Tulsa, Okla, USA. 1981.
80. Tiwari, A., Sain, K., Kumar, A., Tiwari, J., Paul, A., Kumar, N., Haldar, C., Kumar, S., Pandey, C.P. Potential seismic precursors and surficial dynamics of a deadly Himalayan disaster: An early warning approach. Sci. Rep. 12, 3733, 2022.
81. Udias, A. Principles of Seismology; Cambridge University Press: Cambridge, UK, 1999.
82. Varnes, D.J. Slope movement types and processes. In: Landslides Anlaysis and Control, Editied by: Schuster, R.L. and Krizek, R.J, Spec. Rep. 176, Transp. Res. Board, Natl. Acad. Sci. Washington, DC. pp. 11-33, 1978.
83. Vilajosana, I., Suriñach, E., Abellán, A., Khazaradz, G., Garcia, D., Llosa, J. Rockfall induced seismic signals: case study in Montserrat, Catalonia. Nat. Hazards Earth Syst. Sci. 8, 805-812, 2008.
84. Walsh, B., Jolly, A.D., Procter, J. Calibrating the amplitude source location (ASL) method by using active seismic sources: An example from Te Maari volcano, Tongariro National Park, New Zealand. Geophs. Res. Lett. 44, 3591-3599, 2017.
85. Walter, F., Burtin, A., McArdell, B.W., Hovius, N., Weder, B., Turowski, J.M. Testing seismic amplitude source location for fast debris-flow detection at Illgraben, Switzerland. Nat. Hazards Earth Syst. Sci. 17, 939-955, 2017.
86. Walter, F., Amann, F., Kos, A., Kenner, R., Philips, M., de Preux, A., Huss, M., Tognacca, C., Clinton, J., Diehl, T., Bonanomi, Y. Direct observations of a three million cubic meter rock-slope collapse with almost immediate initiation of ensuing debris flows. Geomorphology. 351:106933, 2020.
87. Wang, C.-C., Chen, P.-C., Lin, C.-R., Kuo, B.-Y. Development of a short-period ocean bottom seismometer in Taiwan. In Proceedings of the 2011 IEEE Symposium on Underwater Technology and Workshop on Scientific Use of Submarine Cables and Related Technologies, Tokyo, Japan, 5-8 April 2011; p. 12031721, 2011.
88. Wieczorek, G.F. Effect of rainfall intensity and duration on debris flows in the central Santa Cruz Mountains, California. In Debris Flows/Avalanches: Process, Recognition, and Mitigation; Costa, J.E., Wieczorek, G.F., Eds.; Geological Society of America: Boulder, CO, USA; pp. 93-104, 1987.
89. Winter, K., Lombardi, D., Diaz-Moreno, A., Bainbridge, R. Monitoring icequakes in East Antarctica with the Raspberry Shake. Seismol. Res. Lett. 92, 2736-2747, 2021.
90. Yamada, M., Matsushi, Y., Chigira, M., Mori, J. Seismic recordings of landslides caused by Typhoon Talas (2011), Japan. Geophs. Res. Lett. 39, L13301, 2012.
91. Yen, L.C. The Application of Seismometer on Monitoring of Low-frequency Ground Vibrations Generated by Debris Flows. Master Thesis, National Cheng Kung University, Taiwan, 2014.
92. Yin, H.Y. Studying and Monitoring the Ground Vibration Generated by Debris Flows. Ph.D. Thesis, National Cheng Kung University, Department of Hydraulic and Ocean Engineering, Tainan, Taiwan, 2005.
93. Zhang, S. A comprehensive approach to the observation and prevention of debris flows in China. Natural Hazards. 7, 1-23, 1993.
94. Zhang, S., Hong, Y., Yu, B. Detecting infrasound emission of debris flow for warning purposes. In Proceedings of the International Symposium Interpraevent, Taipei, Taiwan, 26-30 April 2004. Volume VII, pp. 359-364, 2004.