1. KM3Net… past, present, and future oppurtunities for Oceanography and Geophysics
TRANSFERT OF HEAT
BY DIFFUSION AND MIXING

2. Abyssal temperature and velocity observations performed within the NEMO framework, demonstrated cross-fertilization between subnuclear physics and experimental oceanography.
Data collected in the Ionian abyssal plain showed the presence of abyssal vortices in the EM bottom layer: chains of near-inertially pulsating mesoscale cyclones/anticyclones, embedded in an abyssal current flowing towards North-Northwest.
further complexity to the discussion of structure and evolution of water masses in the EM.

3. Intrinsic importance for geo-hazards
Fruitful collaboration between INFN and INGV led to the development of NEMO-SN-1, the first European cabled seafloor multiparameter observatory.
Seismological data are integrated in the INGV land-based national seismic network
Intrinsic importance for geo-hazards
Submarine landslide signal. Modified from Monna et al. (2014)

4. The present…
…seismic, tectonic (active), geomorphologic (underwater instability), and geochemical (geochemical precursors of seismicity):
deepen the understanding of the tectonic and seismic activity of some multi-kilometer length faults recently identified in the western Ionian Sea.
understand whether the mud volcanoes or venting structures identified in the vicinity of the above-mentioned faults constitute active degassing structures
understand whether the continental margins of eastern Sicily and southern Calabria are subject to submarine gravity movements
SEISMOFAULTS 2017
Exploring the seismic faults of the Ionian Seafloor
(INGV-CNR-University of Roma “La Sapienza”)
Eight Ocean Bottom Seismometers with Hydrophones (OBS/H) installed

5. predicting ocean variability on time scales from seconds to decades
The present…
Ocean climate monitoring: multi-scale processes and their multi-disciplinary nature of time series observations for several Essential Ocean State Variables
predicting ocean variability on time scales from seconds to decades
The Mediterranean Sea is a logistically convenient site for climate monitoring: vicinity of the open, deep ocean to the coasts.
The Ionian Sea is a critical location:
deep water formed in the Adriatic Sea arrive there and mix with other water masses activating the main meridional overturning circulation of the EM
ecosystem structure similar to the one of the Atlantic subtropical gyre with phosphorous limitation and small phytoplankton primary producers

6. The present…
ROLE OF DIFFUSION IN THE ANALYSIS OF THE CTD CAST IN THE IONIAN SEA ?
NEMO-SN1
deeper CTD cast
bottom-intensified mixing is consistent with the observed abyssal
ocean only if the ocean basin has sloping lateral walls

7. Temporal evolution of the deep columns
Deep stations at 4080 m from 1999 to 2011
1999
1999

8. The future…
KM3Net infrastructure offers the opportunity to develop a long, multi-disciplinary time series ocean monitoring site
…where the data acquisition frequency is very high, allowing to adequately resolve the temporal frequency of the ocean state variables.
An innovative Deep Ocean Mooring Observatory (DOMO) should be equipped with:
air-sea interaction measurements such as surface radiation, air temperature, winds, air humidity, waves, dust recording, CO2 fluxes.
water column CTD, nutrients, POC, DOM, chlorophyll and radiation sensors;
Sediment traps;
Acoustic sensors for animal tracking;
Imaging cameras;
Deep sea bottom sensors for temperature, salinity, biochemichemistry and pressure.

9. The future… This will Increase our understanding of:
a) the coupling between atmosphere and ocean and the flux of chemicals through the air-sea interface;
b) the coupled ocean and biogeochemical dynamics at the finest time and vertical space scales;
c) the bottom pressure
c) the sediment flux composition and the sedimentation rates.
Km3NET Deep Ocean Monitoring Observatory will:
1) provide sustained in-situ observations at a fixed open-ocean geographic location (typical record length of at least 5 years)
2) sample frequently enough to resolve tidal and diurnal frequency variability;
3) transmit in real time with telemetry to Copernicus marine Environment Monitoring System and GDACS (Global Data Assembly Centers)

10. A unique opportunity for the geophysical research
Region where very complex and not yet fully understood geodynamic processes take place
KM3Net-It close to the southern termination of the Hyblean-Malta escarpment and to the shallower part of the Calabrian Arc and subduction zone
KM3Net-Gr in correspondence with one of the sectors of the largest active subduction zone in the Mediterranean, the western Hellenic arc.
Large-magnitude earthquakes were generated in the past in both regions, some of which were tsunamigenic. They caused severe death toll and damage along the nearby eastern Sicily coasts.
Sources of geophysical hazard:
Earthquakes
Submarine landslides/turbidity currents
Tsunamis
Importance of geophysical monitoring at depth
Improved understanding of the active geodynamic processes
Improved understanding of seismicity and of margin evolution
Improved hazard assessment for the coasts both in the near- and in the far-field
Improved detection capability in an early warning perspective.
Circles – historical earthquakes from the EMEC (2012) catalogue classified by moment magnitude (Mw)
Light-green shaded areas - Subduction zone areas and contours, from the SHARE-EDSF database (2013)
Sector of Geophysics and Tsunami Research Team
Department of Physics and Astronomy – University of Bologna

11. Different environments – different processes and hazards
Possible monitoring activities:
Seismicity and slope stability/margin dynamics. This can be accomplished with the aid of:
three-component seismometers
seafloor geodesy instruments (acoustic transponders)
inclinometers/extensometers.
sea state at depth: in addition to the instrumentation pertaining to pure oceanography, it would very useful to have a network of sea bottom pressure sensors to track currents and sediment transport patterns, and to detect possible “exceptional” events, such as tsunamis and turbidity currents.
Circles – Seismicity from the ISC catalogue
Sector of Geophysics and Tsunami Research Team
Department of Physics and Astronomy – University of Bologna

12. Application to tsunami early warning –
Scenario of tsunami propagation for a 1693-like event (Mw=7.8)
T=0 min
T=4 min
T=50 min
KM3Net-Gr
KM3Net-It
KM3Net-It
KM3Net-It
One or more pressure sensors installed on the seafloor around the KM3Net-It installation would detect the tsunami arrival close to the source in a very short time (less than 4 minutes), likely not enough to alert the coasts in the near-field (eastern Sicily), but early enough to alert the western Greek coasts, where the waves would be detected by the KM3Net-Gr sensors minutes after the tsunami onset.
Sector of Geophysics and Tsunami Research Team
Department of Physics and Astronomy – University of Bologna

13. Application to tsunami early warning –
Scenario of tsunami propagation for a 365-like event (Mw=8.3)
T=0 min
T=20 min
T=40 min
KM3Net-Gr
KM3Net-Gr
KM3Net-Gr
KM3Net-It
KM3Net-It
KM3Net-It
One or more pressure sensors installed on the seafloor around the KM3Net-Gr installation would detect the coseismic displacement and the subsequent tsunami evolution in time in the source area. This would represent a first piece of information to issue an alert also for distant coasts, such as eastern Sicily, where the tsunami waves would arrive after being detected by the KM3Net-It instruments.
Sector of Geophysics and Tsunami Research Team
Department of Physics and Astronomy – University of Bologna