Temp space - find out temp SQL n usage during ORA-01652

oracle RAC - 4 nodes

DB size: 70 TB

DB version: 11.2.0.4.8

I had a process that failed at 6 a.m. with error, "ORA-01652: unable to extend temp segment by 64 in tablespace PH_TEMP04". 

The temp tablespace ran out of space. Current Temp size is 3 TB.

1.  I would like to figure out what all processes were running at that time

2.  What each processes were consuming the time my process ran out of temp space

3.  how does the temp space works in RAC as far as free space?

4.  is it possible that where the process was running - the instance ran out of temp space but other instance may have free temp space in temp tablespace