The principal goal is to have an in field long term logger working and the sd card have huge power needs compare with the eeprom that is really a low power solution.
Modern SD cards sleep at less than 100 µA.
Here is a link to a Cave Data Logger. This logger records environmental conditions in caves over long periods.
After some work, the Cave Data Logger achieved this:
With a 3xAA power pack now providing almost a year of operation for some sensor configurations.