They monitor earthquakes, which increase in frequency before a volcanic eruption. They watch the shape of a volcano, which increases in steepness before a volcanic eruption. They use satellites to predict eruptions.

A lateral eruption or lateral blast is a volcanic eruption which is directed laterally from a volcano rather than upwards from the summit. Lateral eruptions are caused by the outward expansion of flanks due to rising magma. Breaking occurs at the flanks of volcanoes making it easier for magma to flow outward.

Although there are several factors triggering a volcanic eruption, three predominate: the buoyancy of the magma, the pressure from the exsolved gases in the magma and the injection of a new batch of magma into an already filled magma chamber.

Using the choices below, select the statement that best explains how dissolved gases drive volcanic eruptions. Confining pressure decreases on a rising magma, allowing gas bubbles to expand and fracture the magma. This further decreases pressure on the magma and will result in an explosive event.

Viscosity is a measure of a fluid material’s resistance to flow and results from the internal forces and friction between the material’s molecules. Materials with low viscosity have low resistance to flowing and therefore flow very easily.

Composite volcanoes mostly extrude lava of intermediate silica content and medium to high viscosity known as andesite.

shield volcanoes

What is viscosity? Is a measure of a material’s resistance to flow. The more viscous the material, the greater its resistance to flow.

There are 4 different factors which affect resistance:

• The type of material of which the resistor is made.
• The length of the resistor.
• The thickness of the resistor.
• The temperature of the conductor.

The liquid viscosity is highly affected by the heat. The viscosity decreases with an increase in temperature.

two

Roald Amundsen

Antarctica is the only continent on Earth without a native human population. Since no country owns Antarctica, no visa is required to travel there. If you are a citizen of a country that is a signatory of the Antarctic Treaty, you do need to get permission to travel to Antarctica.

Antarctica wasn’t always a land of ice. Millions of years ago, when the continent was still part of a huge Southern Hemisphere landmass called Gondwana, trees flourished near the South Pole.

Amundsen

The devil’s in the detail enough dogs were killed to feed the hungry men and the rest of the dogs. In terms of transportation, Scott always planned to man-haul using harnesses attached to sledges. This was exhausting work, but he believed it was more noble and less cruel than using animals.

Scott had used dogs on his first (Discovery) expedition and felt they had failed. But on that expedition, the men had not properly understood how to travel on snow with the use of dogs. The party had skis but were too inexperienced to make good use of them.

Scott is presumed to have died on 29 March 1912, or possibly one day later. The positions of the bodies in the tent when it was discovered eight months later suggested that Scott was the last of the three to die.

Gran’s journal records how he and his team found the bodies of Scott – who he refers to as “The Owner” – and his companions on 12 November 1912. “It has happened – we have found what we sought – horrible, ugly fate – Only 11 miles from One Ton Depot – The Owner, Wilson & Birdie.

In November 1912, on the Ross Ice Shelf in Antarctica, the surviving members of Scott’s Terra Nova expedition were searching for their leader. They had discovered the final resting place of Scott and two of his men, Henry “Birdie” Bowers and Edward Wilson.

The seals on the stores of fuel broke, and fuel leaked out, so they didn’t have enough fuel, which contributed to them freezing to death. But Scott also made some terrible, terrible mistakes. He planned on four people going to the pole, but then he changed his mind at the last minute.