21 July, 2009 (16:00 GMT), 5 Merrion Square, Dublin 2.
Speaker: Javier Fullea (DIAS).
Title: Geophysical modelling of the lithosphere-asthenosphere boundary beneath the Atlantic-Mediterranean Transition Region: integrating potential field, surface heat flow, elevation, seismological and petrological data.
Abstract:
In this work we study the present-day thermal and compositional 3D structure of the lithosphere beneath the Atlantic-Mediterranean Transition Region (AMTR) and the lithosphere-asthenosphere interaction from Jurassic times to present. The AMTR comprises the western segment of the Africa-Eurasia plate boundary, encompassing two main large-scale tectonic domains: the Gibraltar Arc System and the Atlas Mountains. We apply an integrated and self-consistent geophysical-petrological methodology (LitMod3D) that combines elevation, gravity, geoid, surface heat flow, and seismic data and
allows modelling of compositional heterogeneities within the lithospheric mantle. Our results reveal large variations in the depth of the Moho and the lithosphere-asthenosphere boundary (LAB) as well as a lack of spatial correlation between the thicknesses of these two boundaries. The Moho essentially mimics the topography with depths ranging from ~10 km beneath the oceanic domains of the Atlantic abyssal plains and the Algerian Basin to >34 km in the Eastern Betics and Rif, the High Atlas mountains, and the Sahara Platform. In contrast, the LAB is shallower beneath the central and eastern Alboran Basin (~70 km) and all along the High, Middle and Anti Atlas (140 km) with values exceeding 230 km beneath the Rif and the Sahara Platform. We find that the average bulk composition of the lithospheric mantle corresponds to that of a typical Tecton (i.e. Phanerozoic) domain, with the exceptions of the Sahara Platform, the Alboran Basin, and Atlas Mountains. Distinct mantle compositions are required in these areas to make model predictions and geophysical observables compatible. We propose that the highly irregular LAB topography is the result of the superposition of three different geodynamic mechanisms, which include shortening and thickening related to NW-SE Iberia-Africa convergence lasting from Late Cretaceous to Recent; impingement of a baby-like mantle plume or small-scale convection beneath the High-Middle Atlas and Anti Atlas commencing in the mid Eocene; and slab roll-back or mantle delamination in the Betic-Rif-Alboran realm acting from early to late Miocene.
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Last Updated: 22nd March 2016 by Anna
2009-07-21 – SEMINAR by Javier Fullea: Geophysical modelling of the lithosphere-asthenosphere boundary beneath the Atlantic-Mediterranean Transition Region: integrating potential field, surface heat flow, elevation, seismological and petrological data
21 July, 2009 (16:00 GMT), 5 Merrion Square, Dublin 2.
Speaker: Javier Fullea (DIAS).
Title: Geophysical modelling of the lithosphere-asthenosphere boundary beneath the Atlantic-Mediterranean Transition Region: integrating potential field, surface heat flow, elevation, seismological and petrological data.
Abstract:
In this work we study the present-day thermal and compositional 3D structure of the lithosphere beneath the Atlantic-Mediterranean Transition Region (AMTR) and the lithosphere-asthenosphere interaction from Jurassic times to present. The AMTR comprises the western segment of the Africa-Eurasia plate boundary, encompassing two main large-scale tectonic domains: the Gibraltar Arc System and the Atlas Mountains. We apply an integrated and self-consistent geophysical-petrological methodology (LitMod3D) that combines elevation, gravity, geoid, surface heat flow, and seismic data and
allows modelling of compositional heterogeneities within the lithospheric mantle. Our results reveal large variations in the depth of the Moho and the lithosphere-asthenosphere boundary (LAB) as well as a lack of spatial correlation between the thicknesses of these two boundaries. The Moho essentially mimics the topography with depths ranging from ~10 km beneath the oceanic domains of the Atlantic abyssal plains and the Algerian Basin to >34 km in the Eastern Betics and Rif, the High Atlas mountains, and the Sahara Platform. In contrast, the LAB is shallower beneath the central and eastern Alboran Basin (~70 km) and all along the High, Middle and Anti Atlas (140 km) with values exceeding 230 km beneath the Rif and the Sahara Platform. We find that the average bulk composition of the lithospheric mantle corresponds to that of a typical Tecton (i.e. Phanerozoic) domain, with the exceptions of the Sahara Platform, the Alboran Basin, and Atlas Mountains. Distinct mantle compositions are required in these areas to make model predictions and geophysical observables compatible. We propose that the highly irregular LAB topography is the result of the superposition of three different geodynamic mechanisms, which include shortening and thickening related to NW-SE Iberia-Africa convergence lasting from Late Cretaceous to Recent; impingement of a baby-like mantle plume or small-scale convection beneath the High-Middle Atlas and Anti Atlas commencing in the mid Eocene; and slab roll-back or mantle delamination in the Betic-Rif-Alboran realm acting from early to late Miocene.
Category: Geophysics Section News & Events
Available to buy on the DIAS bookshop: books.dias.ie/index.php?main… (5/5) #DIASdiscovers #celtic #studies #twopatricks
"In the lives of St. Patrick, the two saints are invariably fused into one", said Prof. O'Rahilly in his lecture. The lecture was a condensation from O’Rahilly’s book “The two Patricks: a lecture on the history of Christianity in fifth-century Ireland”. (4/5)
He was known by his first name Patricius, which in later times would lead to confusion as he was succeeded by another apostle of the same name (Saint Patrick or Patricius in Latin). (3/5)
He spoke on "Palladius and Patrick". Palladius was the first bishop of the Christians of Ireland. (2/5)
Date: 21st March 1942 Paper: The Irish Press Headline: Palladius and Patrick | School Of Celtic Studies Lecture Synopsis: The first public lecture under the auspices of the School of Celtic Studies was delivered in Trinity College by Professor T. F. O'Rahilly in 1942. (1/5)
As part of our ongoing participation in the @HistFest we decided to take a look into the Irish Newspaper Archives and see where DIAS made it into print over the last 80 years. There were so many articles, the hardest part was selecting what we would post. We hope you enjoy!
@AReillyFailte @CultureNight @VisitDublin Thanks Antoinette! Glad you enjoyed 😊
Big thank you to @MartinaPQuinn of @helloalicepr for moderating the discussion, and of course to our panel @NeasaMcG @CormacORafferty and @laoneill111
@CormacORafferty "to cut yourself off from fundamental research means you could miss out on some of the biggest ideas"
@laoneill "it's our job as researchers to keep reminding governments how important basic research is" "For Dev basic research being carried out in Ireland was a badge of pride"
@NeasaMcG Schrödinger's work in causality was not well received by the religious authorities at the time At the same time DIAS did have Catholic priests working on research projects in the early days, so there was not the conflict you might think between science and religion
@laoneill111 Schrödinger was very popular in social circles in Dublin, a bit of a renaissance man
@CormacORafferty Schrödinger was gifted at explaining difficult concepts
@CormacORafferty on how unsuccessful work, in Schrödinger's case, unified field theory, is just as important part of science. And no one has managed to crack it yet! And not forgetting the cat
@laoneill111 how Schrödinger's book inspired scientists to change fields and result in the finding of the double helix.
@NeasaMcG explaining how DIAS came about and how Schrödinger was attracted to Ireland #DIASdiscovers
Panel Discussion getting underway! @laoneill111 @CormacORafferty @NeasaMcG @MartinaPQuinn
We're half way through the documentary... Join us for the rest and the fascinating discussion to follow DM for link