LESSONS LEARNED FROM PAST NOTABLE DISASTERSNEW ZEALANDPART 4: VOLCANOES Walter Hays, Global Alliance for Disaster Reduction, Vienna, Virginia, USA
NATURAL HAZARDS THAT HAVE CAUSED DISASTERS IN NEW ZEALAND FLOODS GOAL: PROTECT PEOPLE AND COMMUNITIES WINDSTORMS EARTHQUAKES HIGH BENEFIT/COST PROGRAMS FOR BECOMING DISASTER RESILIENT VOLCANOES ENVIRONMENTAL CHANGE GLOBAL CLIMATE CHANGE
Natural Phenomena that Cause Disasters Planet Earth’s Restlessness is Caused by Heat Flow, Which Causes Subduction of Some Tectonic Plates, which Causes: • Volcanic Eruptions
New Zealand is in the southwest Pacific Ocean astride the “ring of fire,” a distinct belt of volcanic and earthquake activity that surrounds the Pacific Ocean
To the north of New Zealand and beneath the eastern North Island, the thin, dense, Pacific plate moves down beneath the thicker, lighter Indo-Australian plate in a process known as subduction.
AUCKLAND VOLCANIC FIELD • The Auckland volcanic field underlies much of the metropolitan area of Auckland. • Now dormant, but considered likely to erupt again, the field's many vents have produced a diverse array of explosion craters, scoria cones, and lava flows in the past.
HAZARDS EXPOSURE VULNERABILITY LOCATION ELEMENTS OF VOLCANO RISK RISK
VOLCANO HAZARDS (AKA POTENTIAL DISASTER AGENTS) • VERTICAL PLUME • ASH AND TEPHRA • LATERAL BLAST • PYROCLASTIC FLOWS
VOLCANO HAZARDS (AKA POTENTIAL DISASTER AGENTS) • LAVA FLOWS • LAHARS • EARTHQUAKES (related to movement of lava) • TSUNAMI (sometimes) • “VOLCANIC WINTER”
A DISASTER CAN HAPPENWHEN THE POTENTIAL DISASTER AGENTS OF A VOLCANO INTERACT WITH THE VULNERABLE BUILT ENVIRONMENTS OF NEW ZEALAND’S COMMUNITIES
CAUSES OF RISK LATERAL BLAST PYROCLASTIC FLOWS FLYING DEBRIS VOLCANIC ASH VOLCANIC ERUPTIONS LAVA FLOWS CASE HISTORIES LAHARS TOXIC GASES
A DISASTER is --- --- the set of failures that overwhelm the capability of a community torespond 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 single- 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 NODISASTER 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.
VOLCANO HAZARDS • INVENTORY • VULNERABILITY • LOCATION • PREPAREDNESS • PROTECTION • FORECASTS/SCENARIOS • EMERGENCY RESPONSE • RECOVERY and • RECONSTRUCTION VOLCANO RISK POLICY OPTIONS ACCEPTABLE RISK RISK UNACCEPTABLE RISK VOLCANO DISASTER RESILIENCE DATA BASES AND INFORMATION NEW ZEALAND’S COMMUNITIES HAZARDS: GROUND SHAKING GROUND FAILURE SURFACE FAULTING TECTONIC DEFORMATION TSUNAMI RUN UP AFTERSHOCKS
LESSONS LEARNED ABOUT DISASTER RESILIENCE ALL VOLCANOES PREPAREDNESS FOR THE LIKELY HAZARDS IS ESSENTIAL FOR DISASTER RESILIENCE
LESSONS LEARNED ABOUT DISASTER RESILIENCE ALL VOLCANOES EARL WARNING AND EVACUATION STRATEGIES ARE ESSENTIAL FOR COMMUNITY DISASTER RESILIENCE
LESSONS LEARNED ABOUT DISASTER RESILIENCE • ALL VOLCANOES TIMELY EMERGENCY RESPONSE IS ESSENTIAL FOR DISASTER RESILIENCE
NEW ZEALAND’S NEXT VOLCANIC ERUPTION IS INEVITABLE • ---BUT, IT IS ALWAYS A WAITING GAME WITH A VOLCANO.
New Zealand’s volcanic history dates back 60-130 million years, ranging from supervolcanoes to today’s activity consisting of minor eruptions every few years as a result of NZ’s location in the Pacific Ring of Fire
NEW ZEALAND’S PAST ERUPTIONS • New Zealand has been the site of many large explosive eruptions during the last two million years, including several of the supervolcano size. • Notable eruptions include: Macauley Island, Taupo, Whakamaru, Mangakino, Reporoa, Rotoura, and Haroharo.
TAUPO VOLCANO • The Oruanui eruption, 26,500 years ago from the Taupovolcano, was the world's largest known eruption in the past 70,000 years, with a VEI of 8.
TAUPO VOLCANO • Most of New Zealand was covered with ash that reached 18 cm (7 in) at the Chatham Islands 1,000 km (620 mi) from the volcano.
TAUPO VOLCANO • Subsequent erosion and sedimentation had long-lasting effects on the landscape, causing the Waikato River to shift from the Hauraki Plains to its current course through the Waikato to the Tasman Sea. .
TAUPO VOLCANO • Lake Taupo, New Zealand's largest lake, now fills the caldera formed in this eruption.
Even if future eruptions are minor, the people of New Zealand are still at high risk from the ash fall, lahars, and tsunamis associated with them.