LESSONS LEARNED FROM PAST NOTABLE DISASTERS PERU PART 3: EARTHQUAKES AND HUYACOS Walter Hays, Global Alliance for Disaster Reduction, Vienna, Virginia, USA

TECTONIC PLATES

PERU: ON THE SOUTH AMERICAN TECTONIC PLATE

- - -WITH THE SUBDUCTING NAZCA PLATE ON THE WEST

NATURAL HAZARDS THAT HAVE CAUSED DISASTERS IN PERU FLOODS WINDSTORMS EARTHQUAKES—HUAYCOS-- TSUNAMIS VOLCANOES ENVIRONMENTAL CHANGE GLOBAL CLIMATE CHANGE HIGH BENEFIT/COST PROGRAMS FOR BECOMING DISASTER RESILIENT GOAL: PROTECT PEOPLE AND COMMUNITIES

Peru has a long history of destructive earthquakes.

PERU: SEISMICITY

Natural Phenomena that Cause Disasters Planet Earth’s heat flow and lithospheric interactions cause EARTHQUAKES

A DISASTER is the set of failures that overwhelm the capability of a community to respond without external help when three continuums: 1) people, 2) community (i.e., a set of habitats, livelihoods, and social constructs), and 3) complex events (e.g., earthquakes, landslides,..) intersect at a point in space and time.

Disasters are caused by s ingle- or multiple-event natural hazards that, (for various reasons), cause extreme levels of mortality, morbidity, homelessness, joblessness, economic losses, or environmental impacts.

THE REASONS ARE... When it does happen, the functions of the community’s buildings and infrastructure will be LOST because they are UNPROTECTED with the appropriate codes and standards.

THE REASONS ARE... The community is UN- PREPARED for what will likely happen, not to mention the low-probability of occurrence— high-probability of adverse consequences event.

THE REASONS ARE... The community has NO DISASTER PLANNING SCENARIO or WARNING SYSTEM in place as a strategic framework for concerted local, national, regional, and international countermeasures.

THE REASONS ARE... The community LACKS THE CAPACITY TO RESPOND in a timely manner to the full spectrum of expected and unexpected emergency situations.

THE REASONS ARE... The community is INEFFICIENT during recovery and reconstruction because it HAS NOT LEARNED from either the current experience or the cumulative prior experiences.

TOWARDS EARTHQUAKE DISASTER RESILIENCE

PERU

PERU’S COMMUNITIES DATA BASES AND INFORMATION HAZARDS: GROUND SHAKING GROUND FAILURE SURFACE FAULTING TECTONIC DEFORMATION TSUNAMI RUN UP AFTERSHOCKS QUAKE HAZARDS INVENTORY VULNERABILITY LOCATION EARTHQUAKE RISK RISK ACCEPTABLE RISK UNACCEPTABLE RISK QUAKE DISASTER RESILIENCE PREPAREDNESS PROTECTION FORECASTS/SCENARIOS EMERGENCY RESPONSE RECOVERY and RECONSTRUCTION POLICY OPTIONS

HAZARDSHAZARDS ELEMENTS OF EARTHQUAKE RISK EXPOSUREEXPOSURE VULNERABILITYVULNERABILITY LOCATIONLOCATION RISKRISK

EARTHQUAKE HAZARDS: ARE POTENTIAL DISASTER AGENTS

TECTONIC DEFORMATION EARTHQUAKE TSUNAMI GROUND SHAKING FAULT RUPTURE FOUNDATION FAILURE SITE AMPLIFICATION LIQUEFACTION LANDSLIDESAFTERSHOCKSSEICHE DAMAGE/LOSS DAMAGE/ LOSS DAMAGE/LOSS

EARTHQUAKE HAZARDS MODEL EARTHQUAKE HAZARDS MODEL SEISMICITY TECTONIC SETTING & FAULTS TECTONIC SETTING & FAULTS

GROUND SHAKING

LESSONS LEARNED ABOUT DISASTER RESILIENCE ALL EARTH- QUAKES PREPAREDNESS FOR THE LIKELY GROUND SHAKING IS ESSENTIAL FOR DISASTER RESILIENCE

GROUND FAILURE: LANDSLIDES (HUYACOS) AND LIQUEFACTION

SITING AND BUILDING ON UNSTABLE SLOPES LANDSLIDES SOIL AND ROCK SUCEPTIBLE TO FALLS SOIL AND ROCK SUCEPTIBLE TO TOPPLES SOIL AND ROCK SUCEPTIBLE TO SPREADS SOIL AND ROCK SUSCEPTIBLE TO FLOWS PRECIPITATION THAT TRIGGERS SLOPE FAILURE SHAKING GROUND SHAKING THAT TRIGGERS SLOPE FAILURE CAUSES OF DAMAGE CASE HISTORIES

LESSONS LEARNED ABOUT DISASTER RESILIENCE ALL EARTH- QUAKES PREPAREDNESS FOR THE LIKELY GROUND FAILURE IS ESSENTIAL FOR DISASTER RESILIENCE

WHAT WILL HAPPEN? WHEN THE POTENTIAL DISASTER AGENTS OF AN EARTHQUAKE INTERACT WITH THE BUILT ENVIRONMENTS OF PERU’S COMMUNITIES

EXPOSURE MODEL EXPOSURE MODEL LOCATION OF STRUCTURE IMPORTANCE AND VALUE OF STRUCTURE AND CONTENTS

VULNERABILITY MODEL VULNERABILITY MODEL QUALITY OF DESIGN AND CONSTRUCTION ADEQUACY OF LATERAL-FORCE RESISTING SYSTEM

UNREINFORCED MASONRY, BRICK OR STONE REINFORCED CONCRETE WITH UNREINFORCED WALLS INTENSITY REINFORCED CONCRETE WITH REINFORCEDWALLS STEEL FRAME ALL METAL & WOOD FRAME VVIVIIVIIIIX MEAN DAMAGE RATIO, % OF REPLACEMENT VALUE CONSTRUCTION MATERIALS HAVE DIFFERENT VULNERABILITIES TO GROUND SHAKING

NOTE: PERU IS HOME TO SOME OF THE WORLD’S POOREST OF THE POOR WHO LIVE IN VULNERABLE HOUSING CONSTRUCTED OF ADOBE, OFTEN IN DISASTER PRONE LOCATIONS LIKE THE SANTA RIVER VALLEY

INADEQUATE RESISTANCE TO HORIZONTAL GROUND SHAKING EARTHQUAKES SOIL AMPLIFICATION PERMANENT DISPLACEMENT (SURFACE FAULTING & GROUND FAILURE) IRREGULARITIES IN ELEVATION AND PLAN FIRE FOLLOWING RUPTURE OF UTILITIES LACK OF DETAILING AND CONSTRUCTION MATERIALS INATTENTION TO NON- STRUCTURAL ELEMENTS CAUSES OF DAMAGE “DISASTER LABORATORIES”

LESSONS LEARNED ABOUT DISASTER RESILIENCE ALL EARTH- QUAKES BUILDING CODES AND LIFELINE STANDARDS ARE ESSENTIAL FOR DISASTER RESILIENCE

LESSONS LEARNED ABOUT DISASTER RESILIENCE ALL EARTH- QUAKES TIMELY EMERGENCY RESPONSE IS ESSENTIAL FOR DISASTER RESILIENCE

PERU’S MOST NOTABLE EARTHQUAKE M7.9 : SUNDAY, MAY 31, 1970

THE 4:23 PM, SUNDAY, MAY 31, 1970 EARTHQUAKE—HUYACO (LANDSLIDE) DISASTER

LOCATION

The epicenter was offshore, about 37 km (22 miles) west of Chimbite, a major Peruvian fishing port. Damage reached from Chiclayo in the north to Lima in the south, with coastal towns near the epicenter and towns in the Santa River Valley experiencing the worst damage from ground shaking and a HYUACO.

DAMAGE FROM GROUND SHAKING Damage reached from Chiclayo in the north to Lima in the south. Coastal towns near the epicenter experienced severe damage.

DAMAGE FROM GROUND SHAKING Dwellings were vulnerable to ground shaking and often collapsed in piles of rubble because they were sited on alluvial fill (which amplifies ground shaking) and constructed of adobe (which has very low resistance to ground shaking).

MAY 31, 1970

DAMAGE FROM GROUND SHAKING Chimbote, north of Casma, reported almost 3,000 deaths, and sustained damage to 70 to 80 percent of its structures.

DAMAGE FROM GROUND SHAKING Casma, a coastal city south of Chimbote (the earthquake epicenter) with a population of about 13,000, sustained severe damage to 90 percent of its structures, but had few deaths.

THE HUAYCO Although the earthquake ground shaking alone caused death and destruction, severe losses were also caused by a HUAYCO, which swept down the steep slopes of the Cordillera Blanca into the Callejón del Huaylas, a steep valley paralleling the coast.

MAY 31, 1970

MAY 31, 1970: THE HUYACO

DESTRUCTION FROM THE HUYACO

IMPACTS OF THE HUYACO The Huyaco damaged more than 70 percent of the buildings in the Santa River Valley, and took an estimated 20,000 lives.

YUNGAY BURIED BY THE HUAYCO Yungay: thousands of its residents were buried under more than ten meters of mud, earth, water, boulders, and debris.

THE MAY 31, 1970 HUYACO DISASTER MERMORIAL

DEATH TOLL OF THE DISASTER The death toll will never be known for certain. Five days after the earthquake, Peruvian officials feared the death toll would reach 30,000; several days later that figure was raised to 50,000, and on July 14, Peru's Minister of Health estimated the number of dead and missing persons to be 70,000.

ECONOMIC IMPACTS The economic losses from the earthquake and massive HUYACO were assessed at $530 million, --- But, how does one assess the value of communities like Yungay that were totally destroyed or the dislocation cost for nearly 1 million homeless people?

PERU’S NEXT EARTHQUAKE IS INEVITABLE THE PERUVIANS HAVE A MUCH BETTER UNDERSTANDING OF THE IMPORTANCE OF EARTHQUAKE DISASTER RESILIENCE SINCE THE MAY 31, 1970 DISASTER