Come sta cambiando la Terra Solida a causa della propria dinamica interna - Roberto Sabadini Università degli Studi di Milano 105 Congresso SIF ...
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Come sta cambiando la Terra Solida
a causa della propria dinamica interna
Roberto Sabadini
Università degli Studi di Milano
105° Congresso SIF, L’Aquila 2019
Relazione generale
Geofisica e fisica dell’ ambiente
Maxwell Rheology
SUBDUCTION ocean-continent Modelling of slow tectonics Us=5 cm/yr θs=45° cf=1
TEMPERATURE AND VELOCITY FIELDS
• The cold lithosphere sinks into hot
mantle and progressively steepens at
great depths.
• The convective flow characterizes, at
the beginning of subduction, the
area below the subducting plate,
and progressively enlarges below the
upper plate.
• The hot mantle rises in the wedge
area producing a progressive
thermal thinning of the overriding
plate.
TEMPERATURE
Courtesy from Prof. Anna Maria Marotta, Department of Earth Sciences, University of Milano
Location of subduction zones Courtesy from Prof. Anna Maria Marotta, Department of Earth Sciences, University of Milano
Pleistocene Deglaciation Model
ICE-3G
14 kyr BP
9 kyr BP
Ice (m/kyr)
The Post Glacial Rebound
Isostatic Adjustment
core core
Deglaciation mantle
mantle
Isostatic
Adjustment
core
The Mantle Viscosity
mantle drives the Rebound
Satellite data (GRACE, GOCE, GPS) Two kinds of data: - Perturbations in the gravitational field (GRACE, GOCE) - Surface displacements (GPS)
GRACE GOCE
Gravitational field
Some concepts here developed are based on the NGGM
(Next Generation Gravity Mission) techonological and
geodetic feasibility of measuring, at the Geoid (mean sea-
level, no dynamics), a gravitational signal of
1 microGal/yr
at 80 km spatial resolution
(230 spherical harmonics)
In order to have the physical flavor of this accuracy, it is like
adding or removing from the surface of the Earth a plate of
1 cm per year of crustal material, or 2.7 cm of water, sitting
on itGRAVITATIONAL SEISMOLOGY
(Activity Line 1: Scientific Data Exploitation)
ESA ITT AO/1-9101/17/I-NB
Final Meeting Meeting, ESRIN, June 11-12, 2019COURTESY FROM THALES ALENIA SPACE IN ITALY
Future evolution: Next Generation Gravity Mission (NGGM)
Satellite 2
Satellite 1
Mission scenario: two pairs of satellites flying on near-polar (88°) and medium inclination (66°) orbits with mean
altitude between 340 and 370 km and 100 km inter-satellite distance. Target lifetime ∼11 years.
Technique: measurement of the inter-satellite distance variation induced by Earth’s gravity (LL-SST, same of GRACE)
Payload: laser interferometer for inter-satellite distance variation measurement( ∼10 nm/√Hz) + new generation
electrostatic accelerometer for non-gravitational acceleration measurements (∼10-11 m/s2/√Hz between 10-3 - 10-1
Hz).
Improvements w.r.t. GRACE, GOCE: temporal & spatial aliasing reduction in gravity field solutions (2 pairs);
enhanced sensitivity (adequate for detecting time-variability in Earth gravity field) at higher spatial resolution (laser
interferometer, low altitude, drag control).
Gravitational Seismology, KO draft agenda, Milano, 2018 April
5Profiling the Earth, gravitationally
Surface Displacements Accuracy: 1 mm/yr over 1000 km, or 1 nano-strain/yr
EIGEN−6C4
δgSA, 0.1o x 0.1o, 5 km above Ellipsoid −200 −160 −120 −80 −40 0 40 80 120 160 200
wrms about mean / min / max = 34.77 / −350.7 / 664.3 mgal
ICGEM, GFZ Potsdam, Wed Feb 27 10:16:20 2019
http://icgem.gfz-potsdam.deGeneral Scheme
Satellite Solid Earth Phenomena:
Data Model Predictions
Inversion
Earthquake parameters
Present day mass changes
Mantle viscosityAugust 2002
From GRACEApril 2007
Periodic Signal
Semi-Annual
Annual 9-month 7.2-monthThe Map of Mass Variation
Trend - Filtered9 GRACE mass variation trend in water equivalent, after removal of PGR contribution, based on the model ... V.R. Barletta, R. Sabadini, A. Bordoni (2008). Isolating the PGR signal in the GRACE data: impact on mass balance estimates in Antarctica and Greenland. GEOPHYSICAL JOURNAL INTERNATIONAL, vol. 172, p. 18-30, ISSN: 0956-540X, doi: 10.1111/j.1365-246X. 2007.03630.x
3 PGR final results. Upper and lower bounds for the PGR contribution to mass trends in Antarctica and ... V.R. Barletta, R. Sabadini, A. Bordoni (2008). Isolating the PGR signal in the GRACE data: impact on mass balance estimates in Antarctica and Greenland. GEOPHYSICAL JOURNAL INTERNATIONAL, vol. 172, p. 18-30, ISSN: 0956-540X, doi: 10.1111/j.1365-246X. 2007.03630.x
SUBDUCTION ocean-continent Modelling of slow tectonics Us=5 cm/yr θs=45° cf=0.25
CASE STUDIES Sumatra, Marianas
From Marotta et al., GJI 2019, submittedG. Cambiotti, A. Bordoni, R. Sabadini, L. Colli (2011). GRACE gravity data help constraining seismic models of the 2004 Sumatran earthquake. JOURNAL OF GEOPHYSICAL RESEARCH. SOLID EARTH, vol. 116, ISSN: 0148-0227, doi: 10.1029/2010JB007848
Tohoku-Oki earthquake
(Mw=9.1), 2011
Pacific Ocean
National Natural Science Foundation of China (No. 41331066 and
41174063), by the CAS/CAFEA international partnership program for
creative research teams (No.KZZD-EW-TZ-19), and the SKLGED
foundation (SKLGED2014-1-1-E), as well as by the GOCE Italy
Project, the Italian Space Agency and the European Space Agency10 10
GRACE
fitting
5 jump
5
gravity changes (µGal)
gravity changes (µGal)
0
0
−5
−10
−5
(a) A(138°,39°) (b) B(144°,35.5°)
−15 2004 2006 2006 2008 2010
2008 2010 2012 2014 2004 2012 2014
time (year)
time (year)
coseismic gravity changes errors
50˚ 50˚
45˚ 45˚
40˚ 40˚
A
B
35˚ 35˚
30˚ 30˚
(c) (d)
25˚ 25˚
130˚ 135˚ 140˚ 145˚ 150˚ 155˚ 130˚ 135˚ 140˚ 145˚ 150˚ 155˚
µGal µGal
−10 −5 0 5 10 0.0 0.5 1.0 1.5 2.0G. Cambiotti, R. Sabadini (2013). Gravitational seismology retrieving Centroid-Moment- Tensor solution of the 2011 Tohoku earthquake. JOURNAL OF GEOPHYSICAL RESEARCH. SOLID EARTH, vol. 118, p. 183-194, ISSN: 2169-9356, doi: 10.1029/2012JB009555
Gravitational Centroid Moment Tensor Solution G. Cambiotti, R. Sabadini (2013). Gravitational seismology retrieving Centroid-Moment-Tensor solution of the 2011 Tohoku earthquake. JOURNAL OF GEOPHYSICAL RESEARCH. SOLID EARTH, vol. 118, p. 183-194, ISSN: 2169-9356, doi: 10.1029/2012JB009555
Co‐seismic slip distribution of the 2011 Tohoku (MW 9.0) earthquake inverted from GPS and space‐borne
gravimetric data
Earth and Planetary Physics, Volume: 2, Issue: 2, Pages: 120-138, First published: 02 May 2018, DOI: (10.26464/epp2018013)IVONE JIMENEZ-MUNT, SABADINI R, ANNALISA GARDI, GIUSEPPE BIANCO (2003). Active deformation in the Mediterranean from Gibraltar to Anatolia inferred from numerical modeling and geodetic and seismological data. JOURNAL OF GEOPHYSICAL RESEARCH, vol. 108 no. B1, p. ETG 2-1, 2, ISSN: 0148-0227
Figure 2. (a) GPS velocities and 95 per cent confidence ellipses in a fixed Eurasian reference frame (Altamimi ... On the present-day crustal stress, strain-rate fields and mantle anisotropy pattern of Italy , Mimmo Palano, Geophysical Journal International, Volume 200, Issue 2, February, 2015, Pages 969–985, https://doi.org/10.1093/gji/ggu451
G. Cambiotti, X. Zhou, F. Sparracino, R. Sabadini, W. Sun (2017). Joint estimate of the rupture area and slip distribution of the 2009 L’Aquila earthquake by a Bayesian inversion of GPS data. GEOPHYSICAL JOURNAL INTERNATIONAL, vol. 209, p. 992-1003, ISSN: 0956-540X, doi: 10.1093/gji/ggx060
Antonella Amoruso, Luca Crescentini and Andrea Morelli, Slow rupture of an aseismic fault in a seismogenic region of Central Italy, Geophysical Research Letters, 2002, Vol. 29, Issue 24, Pages 72-1-72-4
Livellazione da parte dell’Istituto Geografico Militare dopo il terremoto dell’Irpinia
1980-1985G. Dalla Via, R. Sabadini, G. De Natale, F. Pingue (2005). Lithospheric rheology in southern Italy inferred from postseismic viscoelastic relaxation following the 1980 Irpinia earthquake. JOURNAL OF GEOPHYSICAL RESEARCH: SOLID EARTH, ISSN: 0148-0227, doi: 10.1029/2004JB003539
Segnale gravitazionale di un terremoto di magnitudo
Mw=7.0, come il terremoto del’Irpinia del 1980
Cosismico più postsismico, circa 3 microGal
durante gli 11 anni di durata della missione NGGMEARTHQUAKE MEASUREMENT NGGM
SCENARIOS ERRORS SIMULATION
• Self-gravitating Compressible • Accelerometers and Interferometer • Orbit simulation
Viscoelastic Earth model
• Coloured noise • Noise simulation
based on PREM • Drag force • 28 dat (mean) gravity field retrival
DETECTION of the earthquake signature and discrimination from the
AOHIS (Atmosphere, Ocean, Hydrology, continental Ice, Solid Earth) signals
Courtesy from Dr. Gabriele Cambiotti, Department of Earth Sciences, University of MilanoGrazie L’Aquila di
ospitare il 105°
Congresso Nazionale
della Società Italiana
di Fisica 2019You can also read
