Nature 396, 741– 743 (1998)

We regret that some numbers from an earlier iteration of our calculations were mistakenly used in Fig. 2b and Table 1. The correct figure and table are presented here.

Figure 2: Comparison of results from experiments and theories with seismic observations.
figure 1

Symbols are defined in the original figure.

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Table 1 Elasticity of h.c.p. Fe at 298 K and high pressures
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In Fig. 2b, the aggregate V P of Fe calculated from diamond-cell data of K and G (Fig. 2a) are in excellent agreement with low-pressure ultrasonic data, and compare favourably with high-pressure shock-wave and inner-core values at high temperatures (dVP/d T = −2.9 × 10−4 km s−1 K−1), thus strengthening our original conclusions.

The single-crystal V P anisotropies for Fe at 39 GPa and 211 GPa (in our original Fig. 4), as calculated from C ij values based on isostress assumption, are now similar in magnitude (∼8%) as well as in orientation (minima at a - and c -axes and maximum at 45° to the c -axis). Other parts of this Letter, including the discussion, remain unchanged.

We thank I. Jackson, G. Steinle-Neumann, S. Singh and L.Dubrovinsky for pointing out the inconsistency.