Underwater geophysical monitoring for European Multidisciplinary Seafloor and water column Observatories

Abstract We present a review of our work on data acquired by GEOSTAR-class (GEophysical and Oceanographic STation for Abyssal Research) observatories deployed at three EMSO (European Multidisciplinary Seafloor and water-column Observatory; http://www.emso-eu.org ) sites in southern European waters where strong geo-hazards are present: the Western Iberian Margin, the Western Ionian Sea, the Marmara Sea, and the Marsili basin in the Tyrrhenian Sea. A procedure for multiparameter data quality control is described. Then we explain why the seafloor is an interesting observation point for geophysical parameters and how it differs from land sites. We consider four interesting geophysical phenomena found at the EMSO sites that are related to geo-hazard. In the first case, we show how unknown seismicity and landslides in the Western Ionian Sea were identified and roughly localised through a single-sensor analysis based on the seismometer. In the second case, we concentrate on the problem of near-coast tsunami generation and describe a Tsunami Early Warning Detection (TEWD) system, tested in the Western Iberian Margin and currently operating in real time at the Western Ionian site. In the third case, we consider two large volcanoes in the central Mediterranean area, Mt. Etna and the Marsili seamount. Signals from the seismometer and gravimeter recorded at the seafloor at 2100 m b.s.l. show various phases of Mt. Etna's 2002–2003 eruption. For the less-known Marsili we illustrate how several indicators coming from different sensors point to hydrothermal activity. A vector magnetometer at the two volcanic sites helps identify the magnetic lithospheric depth. In the fourth and final case, we present a multiparameter analysis which was focused on finding possible correlations between methane seepage and seismic energy release in the Gulf of Izmit (Marmara Sea).

[1]  C. Frohlich,et al.  Evidence that biological activity affects Ocean Bottom Seismograph recordings , 1981, Marine Geophysical Researches.

[2]  L. Matias,et al.  Focal mechanisms for sub‐crustal earthquakes in the Gulf of Cadiz from a dense OBS deployment , 2010 .

[3]  Debi Kilb,et al.  Correlations between earthquakes and large mud volcano eruptions , 2007 .

[4]  Laura Beranzoli,et al.  NEMO-SN1 observatory developments in view of the European Research Infrastructures EMSO and KM3NeT , 2011 .

[5]  Y. Hello,et al.  Monochromatic infra‐sound waves recorded offshore Ecuador: possible evidence of methane release , 2002 .

[6]  L. Lanzerotti,et al.  Reply [to “Comment on ‘Geomagnetic depth sounding by induction arrow representation: A review’ by G. P. Gregori and L. J. Lanzerotti”] , 1982 .

[7]  Laura Graziani,et al.  The New Catalogue of Italian Tsunamis , 2004 .

[8]  Paolo Baldi,et al.  Kinematics of the Western Africa-Eurasia plate boundary from focal mechanisms and GPS data , 2007 .

[9]  NEMO-SN1 (Western Ionian Sea, Off Eastern Sicily): A Cabled Abyssal Observatory With Tsunami Early Warning Capability , 2012 .

[10]  P. Favali,et al.  Extending Magnetic Observations to Seafloor: the case of Geostar and Orion missions in the Adriatic and Tyrrhenian Seas , 2007 .

[11]  P. Favali,et al.  ESONET: An European Sea Observatory Initiative , 2008, OCEANS 2008 - MTS/IEEE Kobe Techno-Ocean.

[12]  James H. Dieterich,et al.  Progressive failure on the North Anatolian fault since 1939 by earthquake stress triggering , 1997 .

[13]  Wolfgang Baumjohann,et al.  Magnetospheric Contributions to the Terrestrial Magnetic Field , 2007 .

[14]  Christoph Waldmann,et al.  EMSO: European multidisciplinary seafloor observatory , 2009, 2011 IEEE Symposium on Underwater Technology and Workshop on Scientific Use of Submarine Cables and Related Technologies.

[15]  Barbara Romanowicz,et al.  Excitation of Earth's continuous free oscillations by atmosphere–ocean–seafloor coupling , 2004, Nature.

[16]  Gianluca Valensise,et al.  The 28 December 1908 Messina Straits Earthquake (MW 7.1): A Great Earthquake throughout a Century of Seismology , 2009 .

[17]  A. Peccerillo.  Plio-Quaternary magmatism in Italy , 2003 .

[18]  J. Gottsmann,et al.  4D volcano gravimetry , 2008 .

[19]  S. Webb,et al.  Broadband seismology and noise under the ocean , 1998 .

[20]  Paolo Favali,et al.  Seafloor Observatory Science , 2010 .

[21]  F. Greco,et al.  Analysis of simultaneous gravity and tremor anomalies observed during the 2002-2003 Etna eruption , 2006 .

[22]  S. Kolesov,et al.  Elastic oscillations of water column in the 2003 Tokachi-oki tsunami source: in-situ measurements and 3-D numerical modelling , 2007 .

[23]  T. Dahm,et al.  New insights on volcanic and tectonic structures of the southern Tyrrhenian (Italy) from marine and land seismic data , 2013 .

[24]  Francesco Gasparoni,et al.  GEOSTAR: a GEophysical and Oceanographic STation for Abyssal Research , 1998 .

[25]  A simple formula for estimating the magnetic fields generated by tsunami flow , 2005 .

[26]  S. Constable.  Marine electromagnetic induction studies , 1990 .

[27]  G. Marinaro,et al.  Monitoring of gas and seismic energy release by multiparametric benthic observatory along the North Anatolian Fault in the Sea of Marmara (NW Turkey) , 2014 .

[28]  Barbara Orecchio,et al.  On the cause of the 1908 Messina tsunami, southern Italy , 2008 .

[29]  K. Kastens,et al.  ODP Leg 107 in the Tyrrhenian Sea: Insights into passive margin and back-arc basin evolution , 1988 .

[30]  Kerry Gallagher,et al.  Reply to comment regarding the ICE-hypothesis , 2009 .

[31]  Bernard A. Chouet,et al.  Long-period volcano seismicity: its source and use in eruption forecasting , 1996, Nature.

[32]  Gu¨nther F. Clauss,et al.  A fleet of multiparameter observatories for geophysical and environmental monitoring at seafloor , 2006 .

[33]  G. Marinaro,et al.  Cold seeps, active faults and the earthquake cycle along the North Anatolian Fault system in the Sea of Marmara (NW Turkey) , 2012 .

[34]  G. Groppelli,et al.  Geological evolution of a complex basaltic stratovolcano: Mount Etna, Italy , 2011 .

[35]  F. Chierici,et al.  Modeling of the hydroacoustic signal and tsunami wave generated by seafloor motion including a porous seabed , 2010 .

[36]  L. Cocchi,et al.  Potential‐field modeling of collapse‐prone submarine volcanoes in the southern Tyrrhenian Sea (Italy) , 2010 .

[37]  M. Longuet-Higgins.  A theory of the origin of microseisms , 1950, Philosophical Transactions of the Royal Society of London. Series A, Mathematical and Physical Sciences.

[38]  Laura Graziani,et al.  Observations of physical effects from tsunamis of December 30, 2002 at Stromboli volcano, southern Italy , 2006 .

[39]  J. Gottsmann,et al.  Oscillations in hydrothermal systems as a source of periodic unrest at caldera volcanoes: Multiparameter insights from Nisyros, Greece , 2007 .

[40]  M. Favalli,et al.  Seismic and landslide source of the 1908 Straits of Messina tsunami (Sicily, Italy) , 2009 .

[41]  N. Sultan,et al.  Microevents produced by gas migration and expulsion at the seabed: a study based on sea bottom recordings from the Sea of Marmara , 2012 .

[42]  W. Crawford,et al.  Shallow-Water Broadband OBS Seismology , 2010 .

[43]  P. Squarci,et al.  Deep temperatures and surface heat flow distribution , 2001 .

[44]  L. Lanzerotti,et al.  Electrical conductivity structure in the lower crust , 1982 .

[45]  Elisa Buforn,et al.  Seismicity, source mechanisms and tectonics of the Azores-Gibraltar plate boundary , 1988 .

[46]  Richard S. Lampitt,et al.  In situ sustained Eulerian observatories , 2010 .

[47]  Thomas B. Sanford,et al.  Motionally Induced Electric and Magnetic Fields in the Sea , 1971 .

[48]  A. Jennings,et al.  Seafloor gas seeps triggered by a northern California earthquake , 1987 .

[49]  P. G. Gibbs,et al.  The Epicentres and Origin Times of Some Large Explosions , 1968 .

[50]  P. Favali,et al.  Low‐frequency seismic signals recorded by OBS at Stromboli volcano (Southern Tyrrhenian Sea) , 2009 .

[51]  P. Favali,et al.  New observations of local seismicity by the SN-1 seafloor observatory in the Ionian Sea, off-shore Eastern Sicily (Italy) , 2007 .

[52]  K. Satake,et al.  Tsunami signals from the 2006 and 2007 Kuril earthquakes detected at a seafloor geomagnetic observatory , 2011 .

[53]  Giuliano F. Panza,et al.  The main characteristics of the lithosphere-asthenosphere system in Italy and surrounding regions , 1980 .

[54]  V. Dekov,et al.  Hydrothermal activity in the SE Tyrrhenian Sea: an overview of 30 years of research , 2004 .

[55]  J. Larsen.  Electric and Magnetic Fields Induced by Deep Sea Tides , 1968 .

[56]  Christoph Waldmann,et al.  Societal need for improved understanding of climate change, anthropogenic impacts, and geo-hazard warning drive development of ocean observatories in European Seas , 2011 .

[57]  R. Azzaro.  Earthquake surface faulting at Mount Etna volcano (Sicily) and implications for active tectonics , 1999 .

[58]  M. Sprovieri,et al.  The Marsili Ridge (Southern Tyrrhenian Sea, Italy): An island-arc volcanic complex emplaced on a ‘relict’ back-arc basin , 2013 .

[59]  T. Trua,et al.  Thermal constriction and slab tearing at the origin of a superinflated spreading ridge: Marsili volcano (Tyrrhenian Sea) , 2002 .

[60]  Gravity fluctuations induced by magma convection at Kīlauea Volcano, Hawai‘i , 2012 .

[61]  P. Favali,et al.  NEMO-SN1 Abyssal Cabled Observatory in the Western Ionian Sea , 2013, IEEE Journal of Oceanic Engineering.

[62]  J. J. Dañobeitia,et al.  The quest for the Africa–Eurasia plate boundary west of the Strait of Gibraltar , 2009 .

[63]  P. Favali,et al.  Tsunami Early Warning System: Deep Sea Measurements in the Source Area , 2011 .

[64]  G. Marinaro,et al.  Gas seepage and seismogenic structures along the North Anatolian Fault in the eastern Sea of Marmara , 2012 .

[65]  Laura Beranzoli,et al.  High quality seismological recordings from the SN‐1 deep seafloor observatory in the Mt. Etna region , 2005 .

[66]  Alan D. Chave,et al.  Hawaii‐2 observatory pioneers opportunities for remote instrumentation in ocean studies , 2000 .

[67]  J. M. Miranda,et al.  Revision of the Portuguese catalog of tsunamis , 2009 .

[68]  M. Molina,et al.  Hydrophilic properties of aged soot , 2005 .

[69]  M. Ripepe,et al.  On the geophysical fingerprint of Vulcanian explosions , 2011 .

[70]  Marco Ligi,et al.  Source of 1755 Lisbon earthquake and tsunami investigated , 2001, Eos, Transactions American Geophysical Union.

[71]  J. M. Miranda,et al.  CONSTRAINS ON THE SOURCE OF THE 1755 LISBON TSUNAMI INFERRED FROM NUMERICAL MODELLING OF HISTORICAL DATA ON THE SOURCE OF THE 1755 LISBON TSUNAMI , 1998 .

[72]  P. Favali,et al.  Seafloor Observatory Science: a review , 2006 .

[73]  G. Heiken.  Plio‐Quaternary Volcanism in Italy. By Angelo Peccerillo. Heidelberg: Springer, 2005. 365 pages, 145 figures, and CD‐ROM. $139.00 cloth. , 2007 .

[74]  R. Schick.  Source mechanism of volcanic earthquakes , 1981 .

[75]  Amos Nur,et al.  The formation of Mount Etna as the consequence of slab rollback , 1999, Nature.

[76]  Review of magnetic field monitoring near active faults and volcanic calderas in California: 1974-1995 , 1998 .

[77]  T. Ohminato.  Characteristics and source modeling of broadband seismic signals associated with the hydrothermal system at Satsuma–Iwojima volcano, Japan , 2006 .

[78]  M. N. Toksöz,et al.  Space-time migration of earthquakes along the North Anatolian fault zone and seismic gaps , 1979 .

[79]  Makoto Okamura,et al.  Seafloor gas seeps and sediment failures triggered by the August 17, 1999 earthquake in the Eastern part of the Gulf of İzmit, Sea of Marmara, NW Turkey , 2005 .

[80]  S. Nooner,et al.  A new sea‐floor gravimeter , 2003 .

[81]  S. Tinti,et al.  A revision of the 1693 eastern Sicily earthquake and , 1998 .

[82]  D. Young,et al.  Coastal submarine hydrothermal activity off northern Baja California , 1978 .

[83]  Daniel E. McNamara,et al.  Ambient Noise Levels in the Continental United States , 2004 .

[84]  A. Argnani,et al.  Malta Escarpment fault zone offshore eastern Sicily: Pliocene‐Quaternary tectonic evolution based on new multichannel seismic data , 2005 .

[85]  P. Favali,et al.  GEOSTAR deep seafloor missions: magnetic data analysis and 1D geoelectric structure underneath the Southern Tyrrhenian Sea , 2009 .

[86]  Valerio Iafolla,et al.  Deep Sea Gravity Measurements: GEOSTAR-2 Mission Results , 2006 .

[87]  M. G. Ferrick,et al.  Source mechanism of volcanic tremor , 1982 .

[88]  J. Díaz,et al.  Atypical seismic signals at the Galicia Margin, North Atlantic Ocean, related to the resonance of subsurface fluid-filled cracks , 2007 .

[89]  F. Chierici,et al.  Neogene Through Quaternary Tectonic Reactivation of SW Iberian Passive Margin , 2004 .

[90]  P. Favali,et al.  ORION-GEOSTAR-3: A Prototype of Seafloor Network of Observatories For Geophysical, Oceanographic And Environmental Monitoring , 2004 .

[91]  P. Favali,et al.  NEMO-SN-1 the first “real-time” seafloor observatory of ESONET , 2006 .

[92]  M. S. Barbano,et al.  Analysis of the seismicity of Southeastern Sicily: a proposed tectonic interpretation , 2000 .

[93]  B. Chouet.  Ground motion in the near field of a fluid‐driven crack and its interpretation in the study of shallow volcanic tremor , 1981 .

[94]  Giuseppe D'Anna,et al.  The INGV's new OBS/H: Analysis of the signals recorded at the Marsili submarine volcano , 2009 .

[95]  G. B. Cimini,et al.  New insights from seismic tomography on the complex geodynamic evolution of two adjacent domains: Gulf of Cadiz and Alboran Sea , 2013 .

[96]  X. Le Pichon,et al.  How far did the surface rupture of the 1999 İzmit earthquake reach in Sea of Marmara? , 2003 .