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
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7. Seed

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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

27. None

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

42. None

43. What if I use wrong density?

44. 150 kg.m-3 250 kg.m-3

45. In conclusion

46. None

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

59. None

60. Joint gz + gzz?

61. Same seed

62. gz gzz

63. gzz Joint

64. gzz Joint

65. single vs joint