Continents of the core
Article Abstract:
Seismic anisotropy occurs in the thermal boundary layer known as the D" which lies 200 km above the core of the earth. The cause of seismic anisotropy in the crust may be due to layered rock fabric caused by subducted crustal slabs. Similar activity in the upper mantle and the inner core possibly occurs due to mineralogical anisotropic nature. Properties of D" such as increase in seismic velocity and waves help in explaining anisotropy. Lack of knowledge about melting points and physical behaviors of the lower mantle minerals creates difficulty in selecting a particular model of D".
Publication Name: Nature
Subject: Zoology and wildlife conservation
ISSN: 0028-0836
Year: 1996
User Contributions:
Comment about this article or add new information about this topic:
A window to the core
Article Abstract:
Geophysical research using data recorded at US and Canadian regional seismographic networks following the May 1992 Chinese nuclear test at Lop Nor reveals a seismically fast layer 130 kilometers (km) thick and 300 km wide at the boundary of the core and mantle. The resolution needed to observe such a mass was obtained by organizing data from 14 regional networks of short-period vertical-component seismometers. The data suggest that the boundary region between mantle and core cannot be viewed as a single homogeneous layer and may be as structurally complex as the crust.
Publication Name: Nature
Subject: Zoology and wildlife conservation
ISSN: 0028-0836
Year: 1993
User Contributions:
Comment about this article or add new information about this topic:
Seismological mapping of fine structure near the base of the Earth's mantle
Article Abstract:
Geophysical research using data recorded at US and Canadian regional seismographic networks following the May 1992 Chinese nuclear test at Lop Nor reveals a seismically fast layer 130 kilometers (km) thick and 300 km wide at the boundary of the core and mantle. The resolution needed to observe such a mass was obtained by organizing data from 14 regional networks of short-period vertical-component seismometers. The data suggest that the boundary region between mantle and core cannot be viewed as a single homogeneous layer and may be as structurally complex as the crust.
Publication Name: Nature
Subject: Zoology and wildlife conservation
ISSN: 0028-0836
Year: 1993
User Contributions:
Comment about this article or add new information about this topic:
- Abstracts: Pressure-induced changes in the compression mechanism of aluminous perovskite in the Earth's mantle. The elastic constants of MgSiO3 perovskite at pressures and temperatures of the Earth's mantle
- Abstracts: Enhanced ventilation of the North Atlantic subtropical gyre thermocline during the last glaciation. Millennial-scale changes in North Atlantic circulation since the last glaciation
- Abstracts: Continuum of overlapping clones spanning the entire human chromosome 21q. Human chromosome 11 DNA sequence and analysis including novel gene identification
- Abstracts: Germany will ease requirements of gene technology laws in bow to researchers. part 2 Germany asked to increase spending on universities
- Abstracts: Evidence of a supernova origin for the black hole in the system GRO J1655-40. High lithium abundance in the secondary of the black-hole binary system V404 Cygni