|
Passage 2 below
READING PASSAGE 2
A Earthquakes can rip apart entire cities and outlying districts, as the 1995 disaster in Kobe, Japan
showed Seismologists, scientists who study earthquakes and related phenomena, have records
dating back to 1556, from the Chinese province of Shensi, which indicate that earthquakes have
been devastating our world for centuries In that instance, a major earthquake is estimated to have
killed nearly 810,000 people, while destroying whole towns and villages More recently, a death toll
of more than 66,000 was recorded in northern Peru in 1970, and 23,000 died in the Guatemala
quake
of 1976
B. The destructiv e forces v\ hich produce earthquakes, usually begin deep below the ground, along
a fault in weaker areas of the earth's rocky outer shell, where sections of rock repeatedly slide past
each other The speed at which the fracture spreads at point of weakness depends upon the type of
rock but may average about 3 km a second in granite or other strong rock At that rate, a fracture
may spread more than 560 km in one direction in less than a minute As the fracture extends along
the tault, blocks of rock on one side of the fault may drop down below the rock on the other side,
move up and o\er the other side, or slide forward past the other The violent shattering of rock
releases energv iruu travels in v\aves, and these seismic wa\es move out from the focus of the
earthquake in all directions As the \\a\es tra\el away from the focus, they grow gradually weaker
generally resulting in the ground shaking less as distances increase
C Geological movements are not the only occurrences to trigger an earthquake Human activity
most often the filling of reservoirs with extraordmanl\ large amounts of water, can also causi
earthquakes 1 ake Mead, on the Colorado Ri\ er in the United btates, was filled in 1935 and was the
first example of an artificial lake being responsible for earthquake activity Similarly, massive
explosions, such as quarrv blasting and nuclear tests can also wreak havoc
D 1 arlhquakes almost ne\ er kill people directly, although that fact is not of much consolation to
reliiliv es and friends who h.u e lost lov ed ones in an earthquake Instead, many deaths and injuries
result from falling objects and collapsing buildings, while fire resulting from broken gas or fallen
power Inns is another danger The Kobe earthquake in January 1995, lasted only 20 seconds, yel
resulted in a death toll of o\er 5,000 and injured approximately 26,000 people Fires burnt out ol
control for several days after the earthquake, which was followed by hundreds of after-shocks
liec.uise of (cars of damage to gas pipelines and any leaks being potentially disastrous, inhabitant
endured Ine/ing u inter conditions
E I ven though earthquake prone countries spend enormous human and financial resources 01
si ismograpliK measurement, as a means of predicting earthquakes, there is a danger in paying toi
mueh heed lo seemingly high risk zones and erecting less stable buildings solely because of then
IH
ing in .1 low risk /one Prior lo the earthquake, Kobe was not regarded as at serious risk, but afte i
the disaster investigation of the damage revealed that nearly all deaths occurred in small building
that shattered rather than tw isted when stressed Coupled with the problem of soft soils, the
building
had little firm support and many crumbled If countries wish to withstand the devastating forces 01
substantial earthquakes and reduce death, injury and property damage, it is important to design
and construct buildings that are earthquake resistant, as well as monitor seismic forces
Questions 16-18
Select words from paragraph B to answer Questions 16-18. Use ONE word for
each answer. Write your answers in the spaces numbered 16-18 on the answer
sheet.
16. Name the precondition needed in rock for below surface fractures to occur.
17. Which term is used for the location of the greatest amount of movement?
18. What action below the surface rock results in seismic waves?
Do'stlaringiz bilan baham: |
