Lesson 2: Faulting and Seismic Zones in the Philippines

Question 1

officially reported to have caused 250,000 deaths of the 750,000 inhabitants

Answer 1

Tangshan, China earthquake (1976)

Question 2

during the Tangshan China earthquake, the city was leveled and over _____ of the city’s 750,000 inhabitants were killed

Answer 2

250,000

Question 3

an earthquake happened on October 15, 2013

Answer 3

Bohol earthquake

Question 4

magnitude of Bohol earthquake

Answer 4

M7.2

Question 5

maximum intensity of Bohol earthquake

Answer 5

IX

Question 6

the epicenter of Bohol earthquake

Answer 6

Inabanga, Bohol

Question 7

damages of an earthquake

Answer 7

• damage to infrastructure
• damage to government building
• collapse of residential structure
• damage to commercial building

Question 8

the Philippine fault is _____ long

Answer 8

1250 km

Question 9

the Philippine fault is an arc-parallel _____ extending NNW parallel to the Philippine archipelago

Answer 9

strike-slip fault

Question 10

this fault traverses Luzon and Mindanao Islands where most economic and population centers of the country
are located

Answer 10

Philippine fault

Question 11

the _____ on the Philippine fault is interpreted to be a result of oblique subduction of the Philippine sea plate beneath the Sunda plate

Answer 11

left-lateral motion

Question 12

GPS surveys depicted _____ left-lateral motion on the Philippine fault

Answer 12

20-30 mm/year

Question 13

it is seismically active with several surface-rupturing earthquakes in the past 200 years

Answer 13

Philippine fault

Question 14

the PFZ traverses the eastern edge of Masbate parallel to the coastline for a length of _____

Answer 14

30 km

Question 15

the calculated slip rate on Masbate island

Answer 15

2 mm/year

Question 16

magnitude of Masbate earthquake 2003

Answer 16

M6.2

Question 17

epicenter of Masbate earthquake 2003

Answer 17

Naro Bay

Question 18

three major segments of the central Philippine fault zone (PFZ)

Answer 18

• Guinyangan fault
• Masbate fault
• Central Leyte fault

Question 19

the location of large major events that have recurrence intervals as short as 65 years

Answer 19

Guinyangan fault

Question 20

a transition zone characterized by large and medium earthquakes accompanied by unusually large ground rupture with post-seismic deformation and possibly slow slip components

Answer 20

Masbate fault

Question 21

recurrence intervals along this zone range from 5 to 10 years

Answer 21

Masbate fault

Question 22

characterized by creep and by medium-sized events usually with clusters of foreshocks that serve as warning to the impending mainshocks

Answer 22

Central Leyte fault (NCLF and SCLF)