When Turkish lender Denizbank paid more than $350 million for the building that houses its headquarters in April, the purchase cemented the bank’s place in Istanbul’s most expensive commercial district.

Yet, almost as soon as the ink had dried on the deal for the imposing 34-story tower, the same institution was quietly scouting for an alternative premises in another city. The reason wasn’t because of a seismic shift in its business, it was the prospect of seismic activity beneath it.

Earthquakes are unpredictable but also inevitable, and experts say Istanbul might be due one. After the devastation last year in the southeast of the country and criticism the authorities weren’t prepared, banks are now getting ahead on contingency planning. That includes establishing teams in shadow offices in the capital Ankara to ensure continuity should disaster strike.