There are no towns near the Laki craters, but there is a cell tower on a nearby ridge and a hydroelectric plant within the Skaftá River Gorge. While explosive volcanic hazards like ashfall are not impacted by topography at all, lava flows are significantly influenced by topography. Lava, like water, tends to follow the path of least resistance. This usually means flowing downhill. Which of the two pieces of infrastructure is at greater risk from lava flows if Laki were to have another large eruption?  

Laki is the name given to a series of volcanic fissures that erupted catastrophically in 1783. Over the course of five months, the fissures emitted approximately 14 km3 of lava and vast quantities of volcanic gases. Nearly a quarter of all Icelanders perished as a result of the famine this eruption caused.Watch the video on Laki below. Laki Volcanic FissuresLinks to an external site. Using the information provided, characterize the eruption of Laki in 1783 using the choices below.

Just east of Long Beach is an inlet near Point Lookout. This is an important shipping channel. What structure would you want to install along this inlet to prevent sediments from getting deposited in the channel?

  Ozone molecules in the Earth’s stratosphere act to protect the Earth from ultraviolet radiation from the Sun. The following image shows relative concentrations of O3 (ozone). Click on the area where you would expect ultraviolet radiation to be the highest.

Examine the set of plate boundary images, and select the one that shows subduction.

Chemical composition is the primary control on the relative viscosity of a magma. Which of the following compounds is most influential in determining magmatic viscosity?

During gradual heating of a rock, which type of minerals melts first?

  Another important test is determining how many planes of cleavage a particular mineral has. Look at the mineral below. A knife was used to break the mineral into smaller fragments. How many planes of cleavage does the mineral have?

  Let us look at silicates in a little more detail. Depending on a silicate mineral’s composition, the Si-O tetrahedra that make up the mineral will arrange themselves in different patterns. Drag the silicate framework name to the correct schematic on the image provided.

Yellowstone Caldera is a large volcanic system located in northwest Wyoming. It has erupted catastrophically several times in the last 18 million years with the most recent eruption, called the Lava Creek eruption, occurring approximately 630,000 years ago (0.6 Ma).Watch the video on this most recent eruption, and answer the question that follows. Yellowstone Caldera Ash from the Yellowstone eruption was dispersed as far south as the Gulf of Mexico and as far north as Canada. Use the choices below to characterize the eruption.