We found a match
Your institution may have access to this item. Find your institution then sign in to continue.
- Title
Inversions of Surface Displacements in Scaled Experiments of Analog Magma Intrusion.
- Authors
Poppe, S.; Wauthier, C.; Fontijn, K.
- Abstract
Standard geodetic models simplify magma sheet injection to the opening of geometrically simple dislocations in a linearly elastic, homogeneous medium. Intrusion geometries are often complex, however, and non‐elastic deformation mechanisms can dominate the response of heterogeneous rocks to magma‐induced stresses. We used three‐dimensional near‐surface displacements of a scaled laboratory experiment in which a steeply inclined analog magma sheet was injected into granular material. We ran forward models and inverted for eight parameters of an "Okada‐type" tensile rectangular dislocation in a homogeneous, isotropic, and linearly elastic half‐space. Displacements generated by a forward model largely mismatch the experimental displacements, but full or restricted non‐linear inversions of geometrical parameters reduce the residual displacements. The intrusion opening, dip, depth, and to a lesser degree length and width mismatch the most between the experiment and inversion results, whereas location and strike mismatch the least. Our results challenge assumptions made by many analytical and geodetic models. Plain Language Summary: Standard models of volcano deformation simplify a magma intrusion to simple geometries injected in a medium with simplified mechanical behavior. However, intrusion geometries are often complex in nature. Rocks also predominantly respond in a complex manner to magma intrusion. We used the three‐dimensional displacement of the surface of a scaled laboratory experiment in which golden syrup, a magma analog, was injected into a sand‐plaster mixture, an analog for the Earth's crust. Our forward models and inversions show that the modeled simplified geometry and mechanical response largely mismatch the laboratory experiment outcome as observed in X‐ray Computed Tomography imagery. Our results challenge the assumptions made by models commonly used to model and interpret deformation signals measured in volcanically active areas. Key Points: Analog magma intrusions in granular material are approximated by tensile opening dislocations in a linearly elastic half‐spaceInversion results match analog intrusion x‐y location and strike, but mismatch intrusion dip, opening, and depthSimplifying the host rock response to linear elasticity of homogeneous material results in inaccurate inversion model results
- Subjects
COMPUTED tomography; MAGMAS; CRUST of the earth; GRANULAR materials
- Publication
Geophysical Research Letters, 2024, Vol 51, Issue 8, p1
- ISSN
0094-8276
- Publication type
Article
- DOI
10.1029/2023GL106805