Block flows are thicker than aa or pahoehoe, and when they are molten, they creep along at very slow speeds. The eruptions at North Crater produced block, aa, and finally pahoehoe lava. Hot, fluid pahoehoe flows like a river of molten rock, crusting over to form pressure ridges and a ropy or wrinkled surface. As we have seen, lava can come in many different colors, from basic black, to blue, to rusty red. Remember that the last eruption at Craters of the Moon ended approximately 2,000 years ago and that the average time between periods of volcanic activity is 2,000 years.
Geologists predict that the forces needed to produce a volcanic eruption are slowly building.
It seems safe to say that more volcanic eruptions will occur in the not too distant future.