GasZones

Simply place the Gasdrop (System) via GM (Game Master). You can also place multiple drops.
One Gasdrop will be selected at random from all the placed locations!
Settings in your server's profile folder:

# GasZones - Settings. All times in minutes.
# Changes will take effect after the next server restart.

# Duration of a gas event
eventMinutes=20

# Interval until the next event (randomly chosen between min and max, counted from the start of the last event)
pauseMinMinutes=30
pauseMaxMinutes=60

# Delay after server startup before the first event starts
firstEventMinutes=10

# Maximum number of zones that can be active at the same time
maxActiveZones=1

# Events will only start if at least this many players are online
minPlayers=1

# Save locations set by the Game Master and restore them after a restart (1 = yes, 0 = no)
saveSpots=1