We examined SKS-SKKS splitting intensity discrepancies for phases that sample the
lowermost mantle beneath North America, which has previously been shown to exhibit
seismic anisotropy using other analysis techniques. We examined data from 25 long-
running seismic stations, along with 244 stations of the temporary USArray Transportable
Array, located in the eastern, southeastern and western US We identified 279 high-quality
SKS-SKKS wave pairs that yielded well-constrained splitting intensity measurements for …

Seismic anisotropy has been identified in the lowermost mantle of the Earth, the D" layer, in
numerous studies, although the mechanisms that generate this anisotropy in the D" layer
remain imperfectly known. Anisotropy at the base of the mantle can cause discrepancies in
shear wave splitting between pairs of SKS and SKKS phases; therefore, careful
documentation of SKS-SKKS splitting discrepancies can shed light on D" anisotropy. We
examined SKS and SKKS data from 25 long-running seismic stations in eastern North …