2017 Fiscal Year Final Research Report
Study of deep mantle convection by investigating seismic scattering
| Project/Area Number |
15K05269
|
|---|
| Research Category |
Grant-in-Aid for Scientific Research (C)
|
| Allocation Type | Multi-year Fund |
|---|
| Section | 一般 |
|---|
| Research Field |
Solid earth and planetary physics
|
|---|
| Research Institution | Kyushu University |
|---|
Principal Investigator |
|
|---|
| Project Period (FY) |
2015-04-01 – 2018-03-31
|
| Keywords | mid-lower mantle / S-to-P scattering / array analysis / heterogeneity / basaltic materials / kilometer scale / seismic wave |
|---|
| Outline of Final Research Achievements |
I compiled previous observations of S-to-P scattering waves and showed the distribution of S-to-P scattering objects in the mid-lower mantle beneath circum-Pacific subduction zones. The depth distribution of the S-to-P scatterers shows that the scatterers deeper than 1800 km are extremely rare, and that those in the depth range from 1500 to 1700 km tend to be strong. I next focused on the Tonga-Fiji region and investigated the S-to-P scattering objects in detail. I obtained some observations suggesting the shape and size of the scatterers. I then investigated a strong S-to-P scatterer beneath Peru, South America, and constrained the elastic anomaly and the shape of the scatterer, which has a nearly 10% slower shear velocity and a shape of sheet as thin as 10 km.
|
| Free Research Field |
固体地球物理学
|
