A new island volcano rose above the waterline a few days later.
In the end Kathy sacrifices the final secret of recovering the treasure to save Jim's life, but it does no good to Silver; the mechanism he is told to trigger does not reveal the treasure immedialety, but instead serves to drain the island volcano's crater lake.
From here the island volcano of Alba Patera can be seen far out in the sea to the west and the incredible massif of Olympus Mons rises up over the shoulder of the world far to the southwest.
Jim Tillek had already sailed as far west as the river they had christened the 'Jordan,' and, along with a crew to measure volcanism, as far east as the island volcano whose eruption had interrupted the Thanksgiving feast.
Detailed geological mapping shows that the distribution and orientation of vents and feeder dykes within the volcano have shifted from a triple rift system (typical of most oceanic island volcanoes) to one consisting of a single north-south rift.
They prefer to make their lairs in an island volcano, if possible.
Observers aboard those ships noted that she resembled "an island volcano in eruption".
Hawaiian eruptions are the mildest of all, and are characteristic of the Hawaiian island volcanoes, which all have soft, peaceful-sounding names such as Halemaumau, Kilauea and Mauna Loa.
Generalizing rather, it is probably true to say that Hawaiian-type eruptions are more common on the oceanic island volcanoes than elsewhere (though the examples of Nyiragongo and Nyamlagira emphasize that it is only a generalization), since it is in these environments that the fluid basalt lavas are most likely to be found.
Some basalts do occur in continental areas notably the basaltic flood plateaux mentioned in chapter three, but to see an eruption of basaltic lava taking place, one would have to fly (at short notice) to an oceanic island volcano, such as Iceland.