To increase the amount of virtual memory go to Control Panel > System > Advanced > Performance > Settings > Advanced > Virtual Memory Change > Custom Size > adjust as needed. 2 times your physical RAM is a good minimum and 3 times your physical memory in MB is good for your maximum.
Mafic lavas are lavas rich in iron and magnesium, while being low in silica. Basalt is the solidified version of mafic lava. Mafic lavas are the most common lava type on earth. Mafic lavas are also the hottest lavas and normally erupt at over 900 degrees Celsius - that's 1,650 degrees Fahrenheit!
They hope the lava will stay in the channels and not flow over the houses. There are a lot of factors that cause lava to be different - temperature, chemical composition, and amount of pressure all contribute to different types of volcanic flows. Just by looking at the lava thousands of years after the eruption, you can see exactly what type of flow it was.