As seen, the SL2013sv model resolution is the best of four models to reveal even small-scale details
in the upper mantle, for example, for Siberia, Greenland and the Arctic Ocean basins at 100–250 km (Fig. 1b, c, d)
Nevertheless, three other models display the main large-scale features of the lithosphere structure similarly.
Similar velocity anomalies can be seen, for instance, for SEMum2 and S40RTS at the continental and
oceanic lithosphere parts, depending on their thickness and age: positive dV values are mainly related
to ancient cratons (e.g. North America or Siberia) and negative dV values are distributed at the Arctic
Ocean and also at North Eastern Asia and Alaska zones.
One of the main differences of the models is in the deep structure of the Siberian and East European cratons:
Eurasian segment of SEMum2 displays two intense velocity anomalies related to them, whereas the corresponding
anomalies in the S40RTS model are about two times lower. Also SEMum2 has relatively high-frequency dV anomalies
for the North American craton, mainly for the Greenland territory.
Other depth slices also demonstrate clearer velocity distribution details for SEMum2
slices than for S40RTS and SMEAN2. The negative dV anomaly (-0.5 … -1%) in the Northern Eurasia at the depth
250 km according to SEMum2 can be related to the corresponding LAB rise from 200 to 60–80 km seen in LITHO1
model [Pasyanos et al., 2014]. At the depths 400–650 km (Fig. 1e, f),
it is difficult to reveal specific velocity distributions for all four model, as the velocity amplitudes decrease.
At these depths, the main difference between the SL2013sv and other three models is a strong negative velocity
anomaly related to the Iceland plume that decays with depth in the SL2013sv and SEMum2 models.
On the contrary, the corresponding anomaly remains at all S40RTS and SMEAN2 slices.
The comparison also shows that at depths 0–400 km approximately, SEMum2 demonstrates better spatial
resolution than the S40RTS and SMEAN2 models and also better agrees with the LAB depth data (LITHO1).
Therefore, this model is considered as the best model, alternative to SL2013sv, for the Russian Arctic zone studies.
The dataset includes text data files for the circumpolar arctic region.
Data taken from open sources and are
freely accessible.
The study area extends from 60° to 90° north latitude, covering the entire Arctic.
Data values are rate anomalies in %.
The SL2013sv, S40RTS, and SEMum2 models have a 0.5° latitude step and 0.5°
longitude step, while the SMEAN2 model has a 1/12° (5’) latitude step and a 0.5° longitude step
Data have the following designations:
S40RTS_Arctic.zip – S40RTS seismic tomography model depth slices (0–650 km with a step 50 km);
SEMum2_Arctic.zip – SEMum2 seismic tomography model depth slices (0–650 km with a step 50 km);
SL2013sv_Arctic.zip – SL2013sv seismic tomography model depth slices (50–650 km with a step 50 km);
SMEAN2_Arctic.zip – SMEAN2 seismic tomography model depth slices (0–650 km with a step 50 km);
tomogr_format.pdf - data format descriptions.
References
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