Levels of U.S. aid to Pakistan have waxed and waned since the 1980s, according to American geo-political initiatives. Since 9/11, the country has received $19.34 billion in economic and military aid from the U.S. for its cooperation in the so-called âwar on terror.â.
There are three types of basalt lava flows: pillow, pahoehoe, and aa. Pillow Lava: Pillow lavas are volumetrically the most abundant type because they are erupted at mid-ocean ridges and because they make up the submarine portion of seamounts and large intraplate volcanoes, like the Hawaii-Emperor seamount chain.Pahoehoeâ and âaaâ are Hawaiian words that describe lava. Pahoehoe Lava: Pahoehoe is the second most abundant type of lava flow. Pahoehoe near the coast of Kilauea. Photo by Steve Mattox, 1989.
Volcanoes and Volcanic Eruptions. Magmas and Lava. Since volcanic eruptions are caused by magma (a mixture of liquid rock, crystals, and dissolved gas) expelled onto the Earth's surface, we'll first review the characteristics of magma that we covered previously. Three basic types of magma: Mafic or Basaltic-- SiO2 45-55 wt%, high in Fe, Mg, Ca, low in K, Na.