The Markov Device is a device that was created by Dr. Brion Markov which has the power to cause an earthquake. Developed by Unidac Industries. Malcolm planned to "level the glades" with this device. The first one was initially deactivated by Detective Quentin seconds before activation. However, it was revealed by Malcolm Merlyn, moments before he supposedly died, that there was another Markov device. Malcolm explained that "if there is one thing he learned in business, it would be redundancy". The second device then was activated via timer countdown and began the "earthquake". It destroyed numerous buildings throughout Star City and killed 503 people, including Oliver's best friend and Malcolm's son, Tommy Merlyn.
- The First Device ("Sacrifice") (deactivated by Quentin Lance)
- The Second Device ("Sacrifice") (destroyed during the Glades Earthquake)
- The Prototype Device ("Tremors") (destroyed by Oliver Queen and Roy Harper)
- Earthquake generation: The Markov device can create powerful, artificial earthquakes, destructive enough to level several city blocks or even entire sections of a town.
- "Al Sah-him" (mentioned)
- The name "Markov" and the fact that this device creates earthquakes is a clear allusion to DC character Geo-Force and his sister, Terra, as their real names are Bryan and Tara Markov. Both siblings have powers that manipulate earthly matter, hence the machine's earthquake-triggering ability.