AA is a type of basaltic lava characterized by a rough, jagged surface due to rapid cooling and solidification. Pahoehoe is another type of basaltic lava with a smooth, ropy texture formed when the outer layer of lava cools and solidifies, while the molten interior continues to flow.
The difference between Pahoehoe lava and AA lava is that pahoehoe lava is smooth and AA lava is jagged.
Pahoehoe comes from an explosive eruption, whereas AA comes from quiet eruptions.
Aa is slower, cooler, and has less sillica than pahoehoe. Pahoehoe is faster and moves quickly, and phoehoe has more silica, and is also darker than Aa
Pahoehoe is faster moving lava and AA is slower moving lava. Both types are found in basaltic type eruptions. They have different appearances. Pahoehoe is smooth and ropey where as AA is chunky and rough.(much like top of trees) Often a pahoehoe flow can change to an AA flow depending upon the type of slope it encounters. The steeper the slope the more likely AA lava will be present. Aa has more viscosity than Pahoehoe.
Pahoehoe comes from an explosive eruption, whereas AA comes from quiet eruptions.
Aa and pahoehoe lavas are both basaltic in composition. The lava from composite volcanoes is likely to be granitic.
Aa and pahoehoe are both produced from basalt lava eruptions. The difference in the two being a difference in temperature. Pahoehoe is a hotter flow, moving more smoothly before cooling into rope-like structures. Aa is a bit cooler, forming solid chunks, but continuing to move.
Pahoehoe lava is a lava type flowing from volcanic eruptions. It is not to be confused with Aa lava. Pahoehoe is smooth and ropy lava, cooling into a ropy texture. Aa, on the other hand, is stony and rough. On another note (take this as you will): I would rather stand on Aa lava because it is cooler, characterised simply by its viscosity. Pahoehoe is at around 1100-12000C, as opposed to 1000-1100 for Aa. Please do not stand in either.
Pahoehoe is so much more smoother and duller than AA, because it travels down a gentler slope. You can drive over Pahoehoe. AA, travels down a much steeper slope, and stumbles over itself, and when it hardens, it becomes VERY SHARP AND RAGGED. You wouldn't even be able to walk on AA lava without seriously messing up your feet.
Pahoehoe and AA lava are produced by quiet eruptions. This means that instead of a blast or explosion, the lava just flows out of the volcano. Pahoehoe lava is hot and flows quickly. AA lava is cooler in temperature and doesn't flow as quickly.
Blocky Lava, Pahoehoe Lava, Aa Lava, Pillow Lava
Quiet eruptions