Network
1) How are termites like ants?
(A) They live in groups, and every class has a particular obligation
(B) Their bodies are the same shape
(C) The lord and ruler are detained
(D) They make up every part of the province
(E) The females regenerative limits are the same
2) In line 6, “classes” is nearest in intending to ...
(A) Colleagues
(B) Genders
(C) Settlements
(D) Courses
(E) Classes
3) Which of the accompanying is not genuine?
(A) All termites have eyes
(B) A few termites can’t fly
(C) Termites make up their dominant part of the province
(D) Laborers are littler than fighters
(E) Termites don’t fly frequently
The most common causes of tsunamis are underwater earthquakes. To understand underwater earthquakes, you must first understand plate tectonics. The theory of plate tectonics suggests that the lithosphere, or top layer of the Earth, is made up of a series of huge plates. These plates make up the continents and seafloor. They rest on an underlying viscous layer called the asthenosphere.
Think of pie cut into eight slices. The pie crust would be the lithosphere and the hot, sticky pie filling, underneath would be the asthenosphere. On the earth, this plates are constantly in motion, moving along each other at a speed of 1 to 2 inches (2,5-5 cm) per year. The movement occurs most dramatically along fault lines (where the pies is cut). These motions are capable of producing earthquakes and volcanism, which, when they occur at the bottom of the ocean, are two possible sources of tsunamis.
When two plates come into contact at a region known as a plate boundary, a heavier plate can slip under a lighter one. This is called subduction. Underwater subduction often leaves enormous “handprints” in the form of deep ocean trenches along the seafloor. In some cases of subduction, part of the seafloor connected to the lighter plate may “snap up” suddenly due to pressure from the sinking plate. This results in an earthquake. The focus of the earthquake is the point within the Earth where the rupture first occurs, rock break and the first seismic waves are generated. The epicenter is the point on the seafloor directly above the focus. When this piece of the plate snaps up and sends tons of rock shooting upward with remendous force, the energy of that force is transferred to the water. The energy pushes the water upward above normal sea level. This is birth of a tsunami. The eartquakes that generated the December 26, 2004 tsunami in the Indian Ocean was a 9.0 on the Richter scale – one of the biggest in the recorded history.
