| Attribute | Format | Summary Description | Index |
| AMPID | NUMBER(8) | Primary key to this table | u |
| PHID | NUMBER(8) | External key to the phase table | |
| AMPTYPE | VARCHAR2(8) | Amplitude type | |
| DEPRECATED | VARCHAR2(1) | Flag, set if excluded from the ISC bulletin | |
| DAY | DATE | Time at which amplitude was measured | |
| MSEC | NUMBER(3) | Milliseconds of measurement time | |
| AMP | NUMBER(12,1) | Measured amplitude (Nanometers) | |
| PER | NUMBER(6,2) | Period of measured amplitude (seconds) | |
| DELAMP | NUMBER(10,1) | Uncertainty of amplitude (Nanometers) | |
| DELPER | NUMBER(8) | Uncertainty of period (seconds) | |
| LOGAT | NUMBER(9,2) | Log10(amplitude(nm)/period(sec)) | |
| CHAN | VARCHAR2(3) | FDSN code for channel on which measurements made | |
| MOMENT | NUMBER(8,5) | ||
| FACTOR | NUMBER(8) |
The amplitude.day attribute is the time at which an amplitude was measured, which may differ from the onset time stored in the phase.day attribute.
The deprecated flag is set if ISC has decided not to use the amplitude in computing magnitudes. Such a decision might be set based on lack of consistency with other associated amplitudes, so the deprecated flag should be unset if the amplitudes arrival is disassociated from an event.