| Attribute | Format | Summary Description | Index |
| HYPID | NUMBER(8) | Primary key; external key to hypocenter | u |
| DEPRECATED | VARCHAR2(1) | Status of the hypocentre | |
| SXX | NUMBER(12,4) | x-x component of covariance matrix | |
| SYY | NUMBER(12,4) | y-y component of covariance matrix | |
| SZZ | NUMBER(12,4) | z-z component of covariance matrix | |
| STT | NUMBER(12,4) | t-t component of covariance matrix | |
| SXY | NUMBER(12,4) | x-y component of covariance matrix | |
| SYZ | NUMBER(12,4) | y-z component of covariance matrix | |
| SZX | NUMBER(12,4) | z-x component of covariance matrix | |
| STX | NUMBER(12,4) | t-x component of covariance matrix | |
| STY | NUMBER(12,4) | t-y component of covariance matrix | |
| STZ | NUMBER(12,4) | t-z component of covariance matrix | |
| SDOBS | NUMBER(8,4) | standard deviation of observations | |
| SMAJAX | NUMBER(8,4) | length of ellipse semi-major axis (km) | |
| SMINAX | NUMBER(8,4) | length of ellipse semi-minor axis (km) | |
| STRIKE | NUMBER(4,1) | strike of ellipse semi-major axis (deg) | |
| SDEPTH | NUMBER(6,3) | standard deviation of hypocentral depth | |
| STIME | NUMBER(6,3) | standard deviation of origin time | |
| CONFIDENCE | NUMBER(2) | qualitative confidence measure | |
| AUTHOR | VARCHAR2(16) | Code of agency that created parameters | |
| REPORTER | VARCHAR2(16) | Agency that reported parameters to ISC | |
| LDDATE | DATE | Date loaded in ISC database | |
| MODDATE | DATE | Last date modified | |
| REMID | NUMBER(8) | External key to remark table |
The hypoc_err relation stores information about hypocenter uncertainty. It is a separate relation from hypocenter partly in order to save space, since the ISC lacks uncertainty information for many reported hypocenters. An uncertainty can exist only for a known hypocenter, so if a hypocenter is deleted then the row in hypoc_err should be deleted also. For reported hypocenters, each attribute of hypoc_err is filled only if explicitly reported. For example, even if the associated reading residuals are reported the ISC does not normally compute their standard deviation and record it in hypoc_err.sdobs. The values in a row of hypoc_err may be inconsistent with each other if they are reported that way.