New underwater video reveals sunken vessel deteriorating since last visit in 2022, aiding scientists in their efforts to study rate of liner's decay

Experts have warned the meeting of the molten rock and sea water would likely produce small explosions and release toxic gases that could damage lungs

Atlantic meridional overturning circulation, which includes Gulf Stream, shows signs of tipping into instability, researcher says, warning of potential environmental catastrophe

Vessels departed in May from Iran’s southern port, says deputy army chief, describing their mission as navy's longest, most challenging voyage yet

As Makran and Sahand appear to head for the Atlantic, some American officials worry they are carrying weapons for Venezuela; others expect them to turn back soon