| Abbreviation | Definition |
|---|---|
| A | Australian |
| AADC | Australian Antarctic Data Centre |
| AAG | Association of American Geologists |
| AAOD | Australian Age of Dinosaurs |
| AAPG | American Association of Petroleum Geologists |
| AARS | Asian Association of Remote Sensing |
| AASR | Annual Aquaculture Statistics Report |
| ABFZ | Agua Blanca Fault Zone |
| ABFZ | Angola Benguela Frontal Zone |
| ABFZ | Azores Bank Fracture Zone |
| ABP | Aegean Blue Pearl |
| AC | American Coast |
| ACE | After the Common Era |
| ACH | Aki, Christoffersson, and Husebye |
| ACI | l'Association Cartographique Internationale |
| ACM | Autonomous Crack Monitoring |
| ACP | Active Control Point |
| ACR | Angelo Coast Range |
| ACRC | Australian Crustal Research Centre |
| ACRR | Angelo Coast Range Reserve |