Text and Data Mining valid from 2018-09-17
Received: 10 April 2018
Accepted: 13 August 2018
First Online: 17 September 2018
Change Date: 18 October 2018
Change Type: Correction
Change Details: In the version of this Letter originally published, the unit in the right <i>y</i> axis label in Fig. 3 mistakenly read ‘(m yr<sup>–1</sup>)’; it has now been corrected to read ‘(m Myr<sup>–1</sup>)’.
: The authors declare no competing interests.