(1)证明:∵AO⊥平面A1B1C1,
∴AO⊥B1C1 ,
又∵A1C1⊥B1C1,且A1C1∩AO=0,
∴B1C1⊥平面A1C1CA,∴A1C⊥B1C1,
又∵AA1=AC,
∴四边形A1C1CA为菱形,
∴A1C⊥AC1,且B1C1∩AC1=C1,
∴A1C⊥平面AB1C1,
∴AB1⊥A1C.
(2)∵CC1∥平面AA1B1,
∴点C到平面AA1B2的距离与点C1到平面AA1B1的距离相等,
设C1到平面AA1B1的距离为d,
∵VA?A1B1C1=VC1?AA1B1,
∴
?1 3
?A1C1?B1C1?AO=1 2
?S△AA1B1?d,1 3
又∵在△AA1B1中,A1B1=AB1=2
,AA1=2,S△AA1B1=
2
,
7
∴d=
.2
21
7