Theoretical Frameworks for Tectonic Hazard Prediction and Management

Theoretical Frameworks for Tectonic Hazards

1.8 Theoretical frameworks can be used to understand the predication, impact and management of tectonic hazards.

• a. Understand and explain the role of scientists in predicting and forecasting accuracy, which is dependent on the type and location of the hazard.
• b. Understand the importance of different stages of the hazard management cycle (response, recovery, mitigation, preparedness) and explain the role of emergency planners.
• c. Compare areas at differing stages of development using Park's Model to compare the response curve of hazard events.https://www.bing.com/videos/search?q=chouet +volcano+prediction&&view=detail&mid=CCC C538A9C08A1B1C527CCCC538A9C08A1B1 C527&rvsmid=9D3849670F4F9C78B7149D3 849670F4F9C78B714&FORM=VDQVAP

Natural Hazard Management

1,000 Q1 Q2 Q3 PREDICTION & FORECASTING Q2 Q3 Natural Hazard Management Q4PREDICTION VS FORECASTING

Forecasting refers to the probability of an earthquake event occurring Predicting tries to determine when and where the event will take place. Whether you want a forecast or a prediction (or both) depends on your point of view: Home-owner Local authority Skyscraper architect Insurance companyPREDICTION means knowing in advance exactly when and where a natural hazard will strike ... with sufficient time for evacuation to occur.

Aspects of Prediction

There are 3 aspects to prediction: Spatial prediction (where?) Temporal prediction (when?) Magnitude prediction (How big?)

Volcanic Hazard Prediction

IS IT POSSIBLE TO PREDICT VOLCANIC HAZARDS? Prediction: Yes and no. Comments: Difficult to predict exact time but Volcanoes produce warning signs that can help to evacuate people in time. E.g. An increase in the frequency and intensity of felt earthquakes. Noticeable steaming or fumarolic activity and new or enlarged areas of hot ground. Subtle swelling of the ground surface. Small changes in heat flow. Changes in the composition or relative abundances of volcanic gases

Harmonic Tremors for Volcanic Eruptions

EXAMPLE - HARMONIC TREMORS HAVE BEEN USED IN SOME LOCATIONS TO PREDICT VOLCANIC ERUPTIONS Chouet's break through in 1986 .. Harmonic tremors (long period events) Eg 1993 Galeras Volcano, Colombia Eg 2000 Popocatépetl Volcano, Mexico Watch the video explaining how harmonic tremors were used to predict Popcatepetl eruption in 2000. https://www.bing.com/videos/search?q=chouet +volcano+prediction&&view=detail&mid=9D3 849670F4F9C78B7149D3849670F4F9C78B7 14&&FORM=VRDGARI

Tsunami Hazard Prediction

IS IT POSSIBLE TO PREDICT TSUNAMI HAZARDS? Comments: Trigger for tsunami is often unpredictable (earthquake) However, Tsunami's can be monitored using DART system. Pacific Tsunami Warning Centre (Based in Hawaii, USA) since 1940s Indian Ocean Tsunami Warning System - operational since 2006

DART System for Tsunami Detection

DART system (Deep-ocean Assessment & Reporting of Tsunamis) Although tsunami travel at 500mph it still takes them several hours to cross thousands of miles of ocean so warnings can be given DART II System Bi-directional communication & control Iridium satellite Optional met sensors Wind Barometric Pressure Seasurface Temp & Optional sensor mast Air Temperature/ Relative Humidity Iridium & GPS antennas Lifting handle Tsunami Warning Center 2.0 m Surface Buoy 2.5 m diameter 4000 kg displacement NO Acoustic transducers (2 each) Tsunameter Signal flag Bi-directional, (CCCCCCCCC. Swivel 25 mm nylon Glass ball flotation acoustic telemetry 22 mm nylon 1000-6000 m 13 mm polyester CC ~ 75 m 19 mm nylon Acoustic transducer Acoustic release 13 mm chain (5 m) CPU Batteries Sensor Anchor 3100 kg Anchor 325 kg Australia's tsunami detection system - You Tube Conductivity Electronic systems and batteries 1.8 m 25 mm chain (3.5 m)

Earthquake Hazard Prediction

IS IT POSSIBLE TO PREDICT EARTHQUAKE HAZARDS? Basically - No, not yet! May be impossible - chaos theory ideas BUT lots of things have been tried !....

Foreshocks and Prediction Failure

FORESHOCKS In some cases a large earthquake is preceded by a series of smaller quakes called foreshocks. RESULT: FAILURE TO PREDICT!

Tiltmeters and Prediction Failure

TILTMETERS Measuring tiny changes in the tilt of the ground surface Can indicate stress is building up RESULT: FAILURE TO PREDICT! (ט) Water reservoir Water reservoir Water Water level scale Direction of Earth movement

Electrical Conductivity and Prediction Failure

ELECTRICAL CONDUCTIVITY Solid rocks are very poor conductors of electricity. If rocks are fractured water will percolate through the cracks and decrease the electrical resistance. An increase in electrical conductivity of rocks suggests they are being fractured - perhaps due to strain prior to an earthquake. RESULT: FAILURE TO PREDICT!

Unusual Animal Behaviour and Prediction Failure

UNUSUAL BEHAVIOUR OF ANIMALS! goats refusing to go into their pens cats and dogs carrying offspring outdoors chickens evacuating coops in the night fish swimming about aimlessly birds leaving their nests snakes, lizards and small mammals evacuating burrows deep, cold-water fish found in warmer shallow water insects congregating near the seashores homing pigeons becoming lost or delayed hens laying fewer or no eggs RESULT: FAILURE TO PREDICT!

Japan's Earthquake Early Warning System

COMMENT: EXAMPLE - JAPAN'S EARTHQUAKE EARLY WARNING (EEW) SYSTEM Seismometers on land and seabed detect earthquake P-Waves Damaging L-Waves take slightly longer to arrive Warnings issued via mobile phone apps, TV, radio. In 2011 Japan earthquake EEW issued in Tokyo about 90 seconds before seismic waves struck the city Is a warning of 90s of any use?

Risk Forecasting

RISK FORECASTING is far less precise than prediction. It provides the percentage chance (or probability) of a hazard striking a location. Eg 25% chance of a magnitude 7 earthquake in the next 25 years. Forecasting does not allow evacuation but does encourage preparation.

Earthquake Probability and Magnitude

PROBABILITY OF AN EARTHQUAKE AND LIKELY MAGNITUDE San Francisco Peninsula Parkfield 6 90% Southern East Bay Northern East Bay Southern Santa Cruz Mountains San Bernardino Valley Coachella Valley 8 20% 7 30% San Bernardino Mountains Imperial 7 Fresno 30% 7.5 7.5 6.5 Carrizo 8 30% 40% 50% 6 Likely magnitude San Francisco San Andreas fault 20% 30% 7 Probability Los Angeles 6.5 San Luis Obispo Borrego Mountain Less than 10% Figure 3.10 Probability of occurrence and likely magnitude of earthquakes on the California coast Anza North coast 7 Mojave 7 6.5 Cholame San Jacinto Valley 20% 20% Less than 10% 7.5 7 7 20% 20%

Seismic Gap Theory

SEISMIC GAP THEORY What are Seismic gaps? Regions that have been seismically quiet for some time are probably building up stresses in the rocks. How can seismic gap help predict earthquakes? These regions are potential locations for future earthquakes. The longer the time interval without seismic activity the more strain is being built up and therefore the larger the subsequent earthquake.

Seismic Gap Example

Seismic gap example Sacramento SAN Santa Rosa RODGERS CREEK FAULT Napa 62% Sonoma BO Petaluma CONCORD-GREEN VALLEY FAULT probability for one or more magnitude 6.7 or greater earthquakes from 2003 to 2032. This result incorporates 14% odds of quakes not on shown faults. Novato Vallejo San Rafael 680 Antioch Stockton Walnut Check THROST Danville Oakland FAULT 3% 580 Tracy 21% Livermore Hayward Pleasanton San Mateo Bay FAULT Half Moon Bay 101 Palo Alto 10% San 280 Jose 11% 0 20 MILES 0 20 KILOMETERS SAN 97 Gilroy 10 Santa Cruz Watsonville FAULT Monterey Bay Salinas Monterey Expanding urban areas San MT. DIABLO San Francisco FAULT GREENVILLE Pacific Ocean FAULT HAYWARD · Francisco 3% Pacifica 880 CALAVERAS { Z FAULT % Probability of magnitude 6.7 or greater quakes before 2032 on the indicated fault GREGORIO EXTENT OF RUPTURE IN LOMA PRIETA QUAKE Increasing probability along fault segments SAN FRANCISCO BAY REGION EARTHQUAKE PROBABILITY ANDREAS 4% 27%