Although it's not part of the term 'as asked', it may help to note that seismologists usually refer to 'iso-acceleration contours', not 'iso-acceleration curves' - probably because there are lots of other types of 'curve' involved in their calculations/predictions and it helps to be consistent in the terminology.

Geomagnetics for Aeronautical Safety: A Case Study in and ...
https://books.google.cl/books?isbn=1402050232
Jean L. Rasson, ‎Todor Delipetrov - 2006 - ‎Mathematics
Changing the model's seismic source type (line instead of plane) produces an evident difference in g-contour lines and in iso-acceleration contour lines as well, ...
Seismic Hazard in Mediterranean Regions
https://books.google.cl/books?isbn=9027727791
J. Bonnin, ‎European Mediterranean Seismological Centre - 1988 - ‎Science
For lower magnitude zones, adopting higher maximum magnitudes can have pronounced effects on the iso-acceleration contours of these maps. (10) The ...
Ground Motion and Engineering Seismology
https://books.google.cl/books?isbn=0444600469
A.S. Cakmak - 2013 - ‎Technology & Engineering
SEISMIC HAZARD MAPS: RESULTS AND DISCUSSION As the seismic hazard map an iso—acceleration contour map for the—return period of 575 years is ...
Seismic hazard assessment of Iran - Annals of Geophysics
www.annalsofgeophysics.eu › Home › Vol 42, No 6 (1999) › Tavakoli
by B Tavakoli - ‎1999 - ‎Cited by 68 - ‎Related articles
These maps have been prepared to indicate the earthquake hazard of Iran in the form of iso-acceleration contour lines, and seismic hazard zoning, by using ...