relapse-barking at night in crate

Question
Our 2.5yr old dachshund has been sleeping in crate in family room since arrival at 4 months.  In the last 1 month, she has started to bark at night once left alone, most  recently for 4 nights in a row.  We cannot pin cause to the new behavior.  We don't want to reward the behavior by any attention, but we need to sleep.  For three nights we let her wear herself out.  Last night after 3 hours, husband slept on couch.  When he was in room no barking.  When he left, she would bark. He praised her verbally when she was quite and ignored any barking.  Any suggestions to unlearn the barking at night behavior?  We don't think she is ill; she gets exercise and we do not sense any large changes except for having just had a large earthquake around the time this started (San diego).
Thanks

Answer
She may have found the earthquake quite unsettling.  Any after shocks would be difficult or her too.  Dogs can sense things we can't.  There may be some seismic unrest yet.  Once things settle down, she may be OK.  Until then, she may need the reassurance of company.