Sesión 5-A

Aplicaciones de métodos GPS-GNSS para
la medición precisa (milimétrica) de
deformaciones volcánicas y
desplazamientos tectónicos
Posgrado en Ciencias de la Tierra.
Instituto de Geofísica (UNAM)
Ciudad Universitaria, 23-27 de Junio de 2014
Manuel Berrocoso Domínguez. Laboratorio de Astronomía,
Geodesia y Cartografía. Departamento de Matemáticas.
Facultad de Ciencias. Campus Río San Pedro. Universidad
de Cádiz. Correo-e: [email protected]
LA RED GEODINÁMICA GNSS ISLA DE EL HIERRO
LA RED GEODINÁMICA GNSS ISLA DE EL HIERRO
ESTACIONES IGN-CSIC
ESTACIÓN GRAFCAN
Sólo placa Nubia
Deformación como precursor
Distance variation shows an
important decrease of almost
12 cm/year, mainly observed in
the north component of FRON
station.
The numerous seismic events
in this period are lesser than
2.5 of magnitude.
The accumulate seismic energy
is increasing.
Between the end of August
and the end of September, the
deformation suffers an
acceleration reaching
24cm/year.
The seismic events with
magnitude greater than 2.5 and
accumulated seismic energy
also increase.
(September, 28 – October 10).
Spectacular lithospheric elastic
process.
September, 28 – October, 3: Increase
of LPAL-FRON distance (2 cm).
Seismic swarm with magnitude > 3.5.
Exponential increase of accumulated
seismic energy.
October 3 – 8: Decrease of LPALFRON distance (3 cm).
Seismic events with magnitude > 3.5.
The accumulated seismic energy
continues to increase.
October 8 – 10: Increase of LPALFRON distance (1 cm).
Seismic event with magnitude 4.4
(2011/10/08)
October, 10 : Submarine eruption
starts with 16cm/year deformation
detected (4 cm absolutes).
(September, 28 – October 10).
Spectacular lithospheric elastic
process.
September, 28 – October, 3: Increase
of LPAL-FRON distance (2 cm).
Seismic swarm with magnitude > 3.5.
Exponential increase of accumulated
seismic energy.
October 3 – 8: Decrease of LPALFRON distance (3 cm).
Seismic events with magnitude > 3.5.
The accumulated seismic energy
continues to increase.
October 8 – 10: Increase of LPALFRON distance (1 cm).
Seismic event with magnitude 4.4
(2011/10/08)
October, 10 : Submarine eruption
starts with 16cm/year deformation
detected (4 cm absolutes).
From the eruption starts a new
scenario appears when the
lithospheric elasticity coefficient is
overcame.
Then the deformation analysis must
be qualitative. From October 11 to 31,
the deformation seems to be stable
coinciding with seismic events of
magnitude lesser than 3.0.
The accumulated seismic energy is
also stable. The north component of
FRON seems to show the pre-process
tectonic deformation trend.
The first days of November a new
change in the deformation trend is
observed.
The north component of FRON trend
to the south till January, 2012, when
the tectonic trend is retrieved. This
phase starts with a great number of
seismic events with magnitude bigger
than 4.0, mainly located in the north of
El Hierro Island.
The accumulated seismic energy
increases exponentially. There are
scientific evidences of the occurrence,
on November, 3, of a second
submarine eruption in the north of El
Hierro Island.
After the occurrence of the greater
magnitude seismic event (4.6;
2011/11/11), both volcanic processes
are coincident producing alternative
trends of distance variations
(increase-decrease).
The submarine eruption in the south
(La Restinga) dominates the resultant
of both processes.
Phase 7. From late 2011 to June 2012, the deformation is stable with some seismic
events with magnitude lesser than 3.5. From end of June to mid-July, a reactivation
process is reflected in the deformation and seismic events with magnitude greater
than 3.5.
Phase 8 (September 2012 – January 2013).
Process of deflation and inflation.
Phase 9 (March 2013). A new
change in the deformation trend
coinciding with numerous
seismic events with magnitude
greater than 4.0.
Phase 10 (April 2013 – November
2013). Stable period.
Phase 9 (March 2013). A new change in the deformation trend
coinciding with numerous seismic events with magnitude
greater than 4.0.
Phase 10 (April 2013 – November 2013). Stable period.
Phase 11. A new reactivation process is produced in December 2013.
LOCALIZACIÓN DE LAS FUENTES DE PRESIÓN Y EVOLUCIÓN DEL SISTEMA
∆d : desplazamiento radial
∆h : desplazamiento vertical
h
: altitud del vértice
a
: radio de la fuente
f
: profundidad de la fuente
∆P : cambio de presión hidrostática
µ
: coeficiente de elasticidad de
Lamé
υ
: parámetro de Poisson
En áreas volcánicas:
µ aproximadamente 1 GPa
∆P/µ varía entre un rango de
10-3 a 10-1
υ = 0.25
LOCALIZACIÓN DE LAS FUENTES DE PRESIÓN Y EVOLUCIÓN DEL SISTEMA
The first obtained model, from end-July to end-August, locates the pressure source under
Tanganasoga volcano (in the center of the El Hierro Island) at 10 km deep. This source moves to the
south, to Las Calmas sea, for the second MOGI model, with an increase of volume and decreasing
the depth. The third model shows a source with more volume and displacement to the south.
LOCALIZACIÓN DE LAS FUENTES DE PRESIÓN Y EVOLUCIÓN DEL SISTEMA
LOCALIZACIÓN DE LAS FUENTES DE PRESIÓN Y EVOLUCIÓN DEL SISTEMA
PRONÓSTICO SOBRE LA EVOLUCIÓN A CORTO PLAZO
(FILTRADO PREDICTIVO KALMAN)
PRONÓSTICO SOBRE LA EVOLUCIÓN A CORTO PLAZO
(FILTRADO PREDICTIVO KALMAN)
EL PROCESO DE LA NAVIDAD DE 2013
EL PROCESO DE LA NAVIDAD DE 2013
PROCESADOS HASTA DIA 1 de Enero de 2014
LPAL-FRON
112597,66
112597,66
112597,65
112597,65
112597,64
112597,64
112597,63
112597,63
112597,62
112597,62
346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365
Continúa el cambio de
tendencia en la
Deformación, pero apunta
a un nuevo proceso de
elevación después de la
Subsidencia generalizada del
día anterior
EL PROCESO DE LA NAVIDAD DE 2013
EL PROCESO DE LA NAVIDAD DE 2013
AYER (25 Junio 2014)
ALAJ ( La Gomera)
ICOD ( Tenerife)
IZAN ( Tenerife)
SNMG ( Tenerife)
Estaciones de control
AYER (25 Junio 2014)