Gravity inversion in spherical coordinates using tesseroids

Transcript

1. Gravity inversion in spherical coordinates using tesseroids Leonardo Uieda Valéria C. F. Barbosa
2. vs Cartesian Spherical
3. Existing inversion with tesseroids (Chaves and Ussami, 2013) • Geoid height anomalies • Space domain • Regularization: – Depth-weighted Minimum Volume – Similarity to seismic tomography
4. Adapt Planting anomalous densities (Uieda and Barbosa, 2012)
5. Planting anomalous densities • Space domain • Multicomponent: gravity + gradients • Non-conventional inversion – Growth algorithm – No linear systems – Efficient sensitivity computations
7. Seed
19. Synthetics • Possible applications • Advantages • Shortcomings
20. Lineament with dense rocks (magmatic) Inspired by Chad lineament model (Braitenberg et al, 2011)
21. After Braitenberg et al (2011)
22. After Braitenberg et al (2011)
23. 10º N 300 kg.m-3 2º 8km top=1 km
24. gzz At 20 km
25. Seeds
26. observed predicted
28. What if height=120 km?
29. at 120 km at 20 km
30. observed predicted
31. at 120 km at 20 km
32. Even higher height=270 km
33. at 270 km at 120 km
34. observed predicted
35. at 270 km at 120 km
36. Magmatic underplating Inspired by model of the Paraná basin by Mariani et al (2013)
37. After Mariani et al (2013)
38. After Mariani et al (2013)
39. 10º N 200 kg.m-3 15 km 5º 10º top=30 km
40. gzz at 250 km
41. Seed
43. What if I use wrong density?
44. 150 kg.m-3 250 kg.m-3
45. In conclusion
47. for tesseroids
48. Works well
49. height matters 20km 250km
50. correct dense correct dense
51. Future • Combinations of tensor components • Dipping sources (subducting plate) • Real data (open for collaboration)
52. OPEN SOURCE fatiando.org github.com/leouieda/egu2014
53. Extra
54. (Hypothetical) Mantle Plume Inspired by synthetics in Chaves and Ussami (2013)
55. After Chaves and Ussami (2013)
56. top=100 km 200 km 700 km 2º -50 kg.m-3
57. gzz at 250 km
58. Seed
60. Joint gz + gzz?
61. Same seed
62. gz gzz
63. gzz Joint
64. gzz Joint
65. single vs joint