full transcript
From the Ted Talk by Steven Anderson: What makes volcanoes erupt?
Unscramble the Blue Letters
In February of 1942, Mexican farmer Dionisio Pulido tugohht he heard thunder comnig from his cornfield. However, the sound wasn’t coming from the sky. The source was a large, smoking crack emitting gas and eejcntig rocks. This fissure would come to be known as the volcano Paricutin, and over the next 9 years, its lava and ash would coevr over 200 square km. But where did this new volcano come from, and what triggered its unpredictable eruption?
The story of any volcano begins with magma. Often, this molten rock forms in areas where ocean water is able to slip into the Earth’s mantle and lower the layer’s melting point. The resulting magma tcpalliyy remains under the Earth’s surface thanks to the delicate balance of three goelaogicl factors. The first is lithostatic psseurre. This is the weight of the Earth’s crust pushing down on the magma below. Magma pushes back with the second factor, mttaimsagac pressure. The battle between these forces strains the third factor: the rock strength of the Earth’s curst. Usually, the rock is strong enough and heavy enough to keep the magma in pacle. But when this euqibiirlum is thrown off, the consequences can be explosive.
Open Cloze
In February of 1942, Mexican farmer Dionisio Pulido _______ he heard thunder ______ from his cornfield. However, the sound wasn’t coming from the sky. The source was a large, smoking crack emitting gas and ________ rocks. This fissure would come to be known as the volcano Paricutin, and over the next 9 years, its lava and ash would _____ over 200 square km. But where did this new volcano come from, and what triggered its unpredictable eruption?
The story of any volcano begins with magma. Often, this molten rock forms in areas where ocean water is able to slip into the Earth’s mantle and lower the layer’s melting point. The resulting magma _________ remains under the Earth’s surface thanks to the delicate balance of three __________ factors. The first is lithostatic ________. This is the weight of the Earth’s crust pushing down on the magma below. Magma pushes back with the second factor, ___________ pressure. The battle between these forces strains the third factor: the rock strength of the Earth’s _____. Usually, the rock is strong enough and heavy enough to keep the magma in _____. But when this ___________ is thrown off, the consequences can be explosive.
Solution
- place
- ejecting
- typically
- pressure
- geological
- equilibrium
- crust
- thought
- coming
- magmastatic
- cover
Original Text
In February of 1942, Mexican farmer Dionisio Pulido thought he heard thunder coming from his cornfield. However, the sound wasn’t coming from the sky. The source was a large, smoking crack emitting gas and ejecting rocks. This fissure would come to be known as the volcano Paricutin, and over the next 9 years, its lava and ash would cover over 200 square km. But where did this new volcano come from, and what triggered its unpredictable eruption?
The story of any volcano begins with magma. Often, this molten rock forms in areas where ocean water is able to slip into the Earth’s mantle and lower the layer’s melting point. The resulting magma typically remains under the Earth’s surface thanks to the delicate balance of three geological factors. The first is lithostatic pressure. This is the weight of the Earth’s crust pushing down on the magma below. Magma pushes back with the second factor, magmastatic pressure. The battle between these forces strains the third factor: the rock strength of the Earth’s crust. Usually, the rock is strong enough and heavy enough to keep the magma in place. But when this equilibrium is thrown off, the consequences can be explosive.
Frequently Occurring Word Combinations
ngrams of length 2
collocation |
frequency |
molten rock |
3 |
magmastatic pressure |
3 |
lithostatic pressure |
2 |
rock layer |
2 |
Important Words
- areas
- ash
- balance
- battle
- begins
- coming
- consequences
- cornfield
- cover
- crack
- crust
- delicate
- dionisio
- ejecting
- emitting
- equilibrium
- eruption
- explosive
- factor
- factors
- farmer
- february
- fissure
- forces
- forms
- gas
- geological
- heard
- heavy
- km
- large
- lava
- lithostatic
- magma
- magmastatic
- mantle
- melting
- mexican
- molten
- ocean
- paricutin
- place
- point
- pressure
- pulido
- pushes
- pushing
- remains
- resulting
- rock
- rocks
- sky
- slip
- smoking
- sound
- source
- square
- story
- strains
- strength
- strong
- surface
- thought
- thrown
- thunder
- triggered
- typically
- unpredictable
- volcano
- water
- weight
- years