Transcript volcanoes
LESSONS LEARNED FROM PAST NOTABLE DISASTERS NEW ZEALAND PART 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 HIGH BENEFIT/COST PROGRAMS FOR BECOMING DISASTER RESILIENT WINDSTORMS EARTHQUAKES 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 HAS SOME OF THE GLOBES 1,500 ACTIVE VOLCANOES NEW ZEALAND: LOCATED ASTRIDE TWO CONVERGENT TETONIC PLATES 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. SUBDUCTION BENEATH THE NORTH ISLAND CAUSES VOLCANOES NEW ZEALAND’S VOLCANOES: (VICINITY OF THE NORTH ISLAND) SOME OF NEW ZEALAND’S VOLANOES TAUPO WHITE ISLAND TONGARIRO RUAPEHU THE 140 SQ KM AUCKLAND VOLCANO FIELD AUCKLAND: COEXISTING WITH A VOLCANO FIELD 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. AUCKLAND VOLCANO FIELD AUCKLAND VOLCANO FIELD ONE TREE HILL: AUKLAND VOLCANO FIELD ELEMENTS OF RISK AND DISASTER ELEMENTS OF VOLCANO RISK HAZARDS EXPOSURE RISK VULNERABILITY LOCATION VOLCANO HAZARDS: ARE POTENTIAL DISASTER AGENTS 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 HAPPEN WHEN THE POTENTIAL DISASTER AGENTS OF A VOLCANO INTERACT WITH THE VULNERABLE BUILT ENVIRONMENTS OF NEW ZEALAND’S COMMUNITIES NEW ZEALAND’S CITIES CAUSES OF RISK LATERAL BLAST PYROCLASTIC FLOWS FLYING DEBRIS VOLCANIC ERUPTIONS CASE HISTORIES VOLCANIC ASH LAVA FLOWS LAHARS TOXIC GASES 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 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 UNPREPARED 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. THE ALTERNATIVE TO A DISASTER: VOLCANO DISASTER RESILIENCE VOLCANO RISK • VOLCANO HAZARDS •INVENTORY •VULNERABILITY •LOCATION DATA BASES AND INFORMATION ACCEPTABLE RISK RISK UNACCEPTABLE RISK NEW ZEALAND’S COMMUNITIES VOLCANO DISASTER RESILIENCE POLICY OPTIONS HAZARDS: GROUND SHAKING GROUND FAILURE SURFACE FAULTING TECTONIC DEFORMATION TSUNAMI RUN UP AFTERSHOCKS •PREPAREDNESS •PROTECTION •FORECASTS/SCENARIOS •EMERGENCY RESPONSE •RECOVERY and RECONSTRUCTION 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 HISTORIC VOLCANIC ERUPTIONS 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 Taupo volcano, 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. NEW ZEALAND’S RECENT VOLCANIC ERUPTIONS 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. RUAPEHU • Ruapehu's 1945 eruption dammed its crater with tephra, which contributed to the Tangiwai disaster of December 24, 1953 when the Tangiwai railway bridge across the Whangaehu River collapsed from a revitalized lahar, killing 151. RUAPEHU • Ash plumes from Ruapehu's 1996 eruption forced the closure of eleven airports, including Auckland’s International Airport. EMERGING TECHNOLOGIES FOR VOLCANO DISASTER RESILIENCE • FORECASTS OF ERUPTIONS • MONITORING TECHNOLOGIES (E.G., DEFORMATION, SEISMICITY, GAS EMISSIONS, REMOTE SENSING, WINDS) • WARNING SYSTEMS • DATABASES FOR EACH VOLCANO • COMPUTER MODELS OF VOLCANOES • MAPS • DISASTER SCENARIOS • HAZARD ASSESSMENT • RISK ASSESSMENT