We assemble 3524 quasars from the Sloan Digital Sky Survey (SDSS) with repeated observations to search for variations of the narrow C IV {lambda}{lambda}1548, 1551 and Mg II {lambda}{lambda}2796, 2803 absorption doublets in spectral regions shortward of 7000{AA} in the observed frame, which corresponds to time-scales of about 150-2643d in the quasar rest frame. In these quasar spectra, we detect 3580 CIV absorption systems with z_abs_=1.5188-3.5212 and 1809 MgII absorption systems with z_abs_=0.3948-1.7167. In term of the absorber velocity ({beta}) distribution in the quasar rest frame, we find a substantial number of CIV absorbers with {beta}4{sigma} for {lambda}2796 lines and >3{sigma} for {lambda}2803 lines.

Cone search capability for table J/MNRAS/450/3904/tablea1 (Catalog of C IV {lambda}{lambda}1548, 1551 Absorption Systems)

Cone search capability for table J/MNRAS/450/3904/tablea2 (Catalog of Mg II {lambda}{lambda}2796, 2803 Absorption Systems)