Projects per year
Abstract
Oceanic arcs can provide insight into the processes of crustal growth
and crustal structure. In this work, changes in crustal thickness and
composition along the Lesser Antilles Arc (LAA) are analysed at 10
islands using receiver function (RF) inversions that combine
seismological data with vP/vS ratios estimated
based on crustal lithology. We collected seismic data from various
regional networks to ensure station coverage for every major island in
the LAA from Saba in the north to Grenada in the south. RFs show the
subsurface response of an incoming signal assuming horizontal layering,
where phase conversions highlight discontinuities beneath a station. In
most regions of the Earth, the Mohorovičić discontinuity (Moho) is
seismically stronger than other crustal discontinuities. However, in the
LAA we observe an unusually strong along-arc variation in depth of the
strongest discontinuity, which is difficult to explain by variations in
crustal thickness. Instead, these results suggest that in layered crust,
especially where other discontinuities have a stronger seismic contrast
than the Moho, H–k stacking results can be
easily misinterpreted. To circumvent this problem, an inversion
modelling approach is introduced to investigate the crustal structure in
more detail by building a one-dimensional velocity–depth profile for
each island. Using this method, it is possible to identify any
mid-crustal discontinuity in addition to the Moho. Our results show a
mid-crustal discontinuity at about 10–25 km depth along the arc, with
slightly deeper values in the north (Montserrat to Saba). In general,
the depth of the Moho shows the same pattern with values of around 25 km
(Grenada) to 35 km in the north. The results suggest differences in
magmatic H2O content and differentiation history of each island.
Original language | English |
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Article number | 180764 |
Number of pages | 14 |
Journal | Royal Society Open Science |
Volume | 5 |
Issue number | 11 |
Early online date | 14 Nov 2018 |
DOIs | |
Publication status | Published - Nov 2018 |
Keywords
- island arc
- crustal structure
- seismic properties of rocks
- receiver function
Fingerprint
Dive into the research topics of 'Probing layered arc crust in the Lesser Antilles using receiver functions'. Together they form a unique fingerprint.Projects
- 2 Finished
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Primitive Arc Magmatism - Experimental Constraints and Imlications for Subduction Zone Thermal Structure
Blundy, J. D. (Principal Investigator)
1/08/15 → 31/07/18
Project: Research
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How does crust form at arcs? - a Multidisciplinary Study of the Lesser Antilles Volcanic Arc
Kendall, M. (Principal Investigator)
1/04/13 → 31/03/17
Project: Research