First of all, we want to stress that this reply to the comment by Hijma & Cohen on the paper by Van de Plassche et al. (2010) reflects our personal view and not necessarily the opinion of the first author of the paper under discussion, Orson van de Plassche. After a long career dedicated to sea-level research, Orson passed away on May 4, 2009, and left us with the Vlaardingen data set and his explicit wish to publish this material, which ultimately led to the Van de Plassche et al. (2010) paper. In the present paper we will: (1) give some background information on the Vlaardingen data set and the special circumstances under which the Van de Plassche et al. (2010) paper was written; (2) reply to the comment on the construction of our revised mean sea-level curve (MSL-R2); (3) reply to the comment on our suggestion that the palaeoriver-gradient might influence sea-level jump magnitude calculations.
The paper by Van de Plassche et al. (2010) is primarily based on the Vlaardingen data set that was collected by Orson van de Plassche in the mid-1980s, in a sequel to his PhD project (Van de Plassche, 1982). Soon after the start of the Vlaardingen project Orson became busily occupied with sea-level research in North America, leaving the Vlaardingen data set virtually unpublished (some data were published in Van de Plassche (1995)).