Transcript THE NEPAL EARTHQUAKE OF APRIL 25,2015. Part 9: It Could

THE NEPAL EARTHQUAKE
OF APRIL 25,2015
Part 9: It Could Have Been Worse
Walter Hays, Global Alliance for
Disaster Reduction, Vienna,
Virginia, USA
SEISMOTECTONICS (Credit: AP)
SATURDAY, APRIL 25, 2015
• A massive block of the Earth’s crust,
roughly 125 km (75 miles) long and 61
km (37 miles) wide, lurched 3 m
(10 feet) to the south Saturday over the
course of 30 seconds. Riding atop this
block of the crust was the capital of
Nepal — Kathmandu — and millions of
Nepalese people.
LOCATION MAP (Credit: AP)
KATHMANDU
THE CAPITAL DEVASTATED
GRIM STATISTICS OF THE
DISASTER ON MAY 2ND
OVER 8,000 DEAD AND 14,000 INJURED
WITH THOUSANDS PRESUMED DEAD AND
BURIED IN THE DEBRIS IN CITIES AND
REMOTE VILLAGES THAT WERE TOTALLY
DEVASTATED; - - -
GRIM STATISTICS OF THE
DISASTER (continued)
HOMELESS + DEVASTATED
INFRASTRUCTURE IN A POOR COUNTRY
IS A RECIPE FOR AT LEAST A $2 BILLION
DISASTER AWAITING INTERNATIONAL
ASSISTANCE FOR RECOVERY AND
RECONSTRUCTION; - - -
AS GRIM AS THE REALITY
APPEARS, IT COULD HAVE
BEEN WORSE
IT COULD HAVE BEEN
WORSE
• The epicenter could have been
closer to Kathmandu: i.e.,
much closer than 80 km,
including the “bulls eye”
location, as in the 1976
Tangshan, China earthquake. .
IT COULD HAVE BEEN
WORSE
• The hypocenter could have
been shallower; i.e., 8-10 km
instead of 13 km.
IT COULD HAVE BEEN
WORSE
• The magnitude could have
been larger; i.e., 4 times larger
(M8.2), as in the 1934 Nepal
earthquake.
IT COULD HAVE BEEN
WORSE
• The earthquake could have
occurred at the “worst” time of
day; i.e., 11:56 PM when
everyone is in bed in their
vulnerable homes instead of
11:56 AM when people are
outside their homes.
IT COULD HAVE BEEN
WORSE
• The aftershock sequence, which
will probably last a year, could
have been more vigorous with the
earliest aftershocks having magnitudes near M7, exacerbating
damaged and/or partially collapsed
buildings, and infrastructure.
IT COULD HAVE BEEN
WORSE
• The ground shaking could have
triggered many more landslides,
and mudslides (when combined
with prolonged rainfall), and
avalanches.
IT COULD HAVE BEEN
WORSE
• Some of the landslides could have
dammed rivers, creating
“earthquake lakes”, as in the 2008
Sichuan, China earthquake--increasing the risk from flooding.
IT COULD HAVE BEEN
WORSE
• The “disaster after the disaster”—
infectious diseases and loss of
function of medical facilities—
could have been worse than the
earthquake disaster.
8 MILLION+ IMPACTED (Credit: AP)
8 MILLION+ IMPACTED (Credit: AP)
1.4 MILLION NEEDING TEMP, SHELTER,
FOOD, AND NECESSITIES (Credit: AP)
TEMPORARY HOUSING: ONE OF
THE TENT CAMPS (Credit: AP)
TUESDAY (continued)
THE GOVERNMENT HAD ESTABLISHED
16 LARGE TENT CAMPS IN KATHMANDU;
MANY RSIDENTS CONTINUED SLEEPING
IN THE STREETS OR IN OPEN SPACES
AWAY FROM DAMAGED BUILDINGS,
HOMES, AND WALLS;
“NEPAL WILL
BEBOUND”
Nepal’s Prime minister
BAD NEWS FOR THE FUTURE: Earthquake
experts said Saturday's earthquake did not
release all of the pent-up seismic pressure
in the region near Kathmandu. According to
GPS monitoring and geologic studies,
“some 33 to 50 feet (10 to 15 meters) of
motion may still need to be released,” said
Eric Kirby, a geologist at Oregon State
University.
•MONITORING
•HAZARD MAPS
•INVENTORY
•VULNERABILITY
•LOCATION
DATA BASES
AND INFORMATION
ACCEPTABLE RISK
RISK
UNACCEPTABLE RISK
YOUR
BOOKS OF
KNOWLEDGE
COMMUNITY
EARTHQUAKE DISASTER
RESILIENCE
HAZARDS:
GROUND SHAKING
GROUND FAILURE
SURFACE FAULTING
TECTONIC DEFORMATION
TSUNAMI RUN UP
AFTERSHOCKS
•PREPAREDNESS
•PROTECTION
•EM RESPONSE
•RECOSTRUCTION AND
RECOVERY