#1UMR NORTH SUMATRA - ANDAMAN ISLANDS TSUNAMIS of December 2004 and March 2005 J. David Rogers Department of Geological Sciences & Engineering University of Missouri-Rolla [email protected]#2UMR Dec 26, 2004 North Sumatra Tsunami ■ The most devastating tsunami in modern time was triggered by the Magnitude 9 North Sumatra-Andaman Island earthquake at 6:58 AM local time on Sunday December 26, 2004 ■ It killed approximately 272,000 people#316 Q INDIA Colombo Northeast Indian Ocean Region Seismicity 1900 - 2004, M≥6 BAN H 106 CAINA. Kolkata (Calcutta) Dhaka MYANMAR 6B4RMA) Viangchan Vientiane) BAY OF BENCAL Yangon (Rangoon) THAILAND Krung Thep. Bangkok) Chennai (Madras) Andaman Is ✓ SRI LANKA Hanoi VIET AMBODIANA Anom Penh INDIAN OCEAN MALAYSIA Kuala Lumpur NGAPORE Singapore ONESIA 700 LO O ME Mudo Ago SUNCA TRENCH 1200 Koma Jakarta Historic Seismicity Eastern Indian Ocean 1900 - 2004 ■ The Indian Plate moves northeasterly about 60 mm/yr relative to the Burma Plate, resulting in oblique convergence with the Sunda Trench ■ The last major earthquake in the Sunda Trench was in southeastern Sumatra in 1833. The tsunamis generated by that quake were directed southerly, towards Antarctica. EXPLANATION Main Shock 26 December 2004 O Atershocks M 26 Earthquakes M≥6 0-69 km O 70 - 299 O 300-699 ▲ Volcanoes#4Northeast Indian Ocean Region Tectonic Setting BA INDIA Kolkata (Calcutta) Colombo NDIA PLATE Chennai (Madras) YANGTZE PLATE CHINA Dhaka BURANA PLATE MYANMAR (BURMA) Hanoi AOS BAY OF BENGAL Yangon (Rangoon) Viangchan Vientiane) Andaman Andaman Basin SRI LANKA BURMA MCROPLATE Nicob INDIAN OCEAN EXPLANATION Main Shock 26 December 2004 o Atershocks M 2 4 - Generalized Plate Boundaries Faults (after Pubellier et al., 2004) ✓ Thrust T Normal A Strike-Slip Other Volcanoes Ninety Esst AUSTRALIAPLATE SCALE 20quato 7.00 400 Muco Ado THAILAND Khung Thep… Bangkok) VIET AMBODIA NAM Finom Penh SUNDA PLATE MALAYSIA Kuala Lump Sumatra NGAPORE ingapore NONESIA I SUNDA TRENCH Kamal ZII 1200 1.00 Jakarta A J2 Magnitude 9.0 Sumatra-Andaman Islands Earthquake of Dec 26, 2004 ■The distribution of main and aftershock events suggests that approximately 1200 km of the plate boundary slipped as a result of the 12-26-04 earthquake ■The average displacement on the fault plane was about 15 m, with the sea floor overlying the thrust fault being lifted several meters ▪Energy release equivalent to 31,622 atom bombs used on Hiroshima in 1945. UMR#516 TR Northeast Indian Ocean Region Generalized Seismic Hazard BANGLA INDIA Kolkata. (Calcutta) Dhaka 4. MYANMAR (BURMA) *Hanoi Viangchán iane Colombo BAY OF BENGAL Yangon (Rangoon) THAILAND 'Krung Thep Bangkok) Chennai (Madras) Andaman A Phnom Penh SRI LANKA INDIAN OCEAN EXPLANATION Main Shock 26 December 2004 O Atershocks M ≥ 4 Seismic Hazard 00-0.2 msec* 102 -0.4 0.4-0.8 108 1.61 1.6-3.2 32-6.4 D ווה 40 Simic hand is expend peal and sceleration (PGA) on firm rod, in mind, expect ad to be edad with a proba- bility of ten percent in a 50-year period SCALE 123,00qua Mica Piqdo -II 1,200 1.00 6.4-9.7 요 Volcanoes UMR CHINA. CAMBODIA MALAYSIA Kuala Lumpur VIET SLHE APORE Singapore DONESIA NDATRENCH Kama Jakarta ■ This map shows main and aftershock epicenters along with expected variations in site acceleration ■ The fault-rupture was unimodal, propagating hundreds of kilometers northwesterly from the epicenter (star). ■ The data upon which the USGS modeling is based do not permit confident resolution of the extent of rupture beyond about 500 km northwest of the main- shock epicenter.#690 20 15° EXPLANATION 26 December 2004 MT Selution (HRV)) Gend 40-44 45-43 450-54 55- 65-81 Lagata esa 2 V T-200 Faber Publiert, 20 Th A Fin Fault Model 201 MYANMAR (CURMA) Paqu Hor Campard NANGON Ringen Mobal THAILAND (Mbunit 100' 20 15- ulaka Andaman Isla Tent The buri This chan La A INDIA A Andaman Bagin ANDAMAN SEA R Nicol lands Cror Nahar Ph MALAYSIA Strait of Mate SUND TRENCH FINITE FAULT MODEL Sumatra INDONESIA TRT H Finite Fault Model of the M9.0 Sumatra-Andaman Islands Earthquake of Dec 26, 2004 The USGS finite fault model shown here implies that the width of the earthquake rupture, measured perpendicular to the Sunda trench, was about 150 kilometers, and that the maximum displacement on the fault plane during the 12-26-04 event was about 20 meters. ■ The sea floor overlying the thrust fault would have been uplifted by several meters as a result of the earthquake. The 12-26-04 event has seen some of the largest aftershocks ever recorded in modern time. 100 2:00 SCALE 1:5.500.000 with Extr 400 DISCLAIMER 800#7UMR ■ Advancing crest of the initial tsunami wave gains height as water depth decreases, reflecting off islands, promontories and the coastline itself.#8UMR One of the 572 emerald isles of the Nicobar and Andaman Islands, a chain of atolls, cays and islets 700 km long between Burma and Indonesia, northwest and parallel to the quake epicenters. These islands are only 1 or 2 meters above sea level, and the tsunami waves passed over them#9Don't Be a Curious Bystander Curious bystanders standing on a hardened seawall flock to witness the tsunami waves as they break against a protective breakwater structure Most people have little idea how powerful enormous waves of water can be#10UMR - Never underestimate the unrelenting force of water – it is an incompressible fluid#11Before and after images of coast in northern Banda Aceh, the capital of Ache Province in Northern Sumatra (Indonesia), about 155 miles form the main shock epicenter#12Before and after views of Banda Aceh shoreline ■ Note erosion of shallow unconsolidated sands along the coastline ■ This kind of damage is typical of tsunami waves#13UMR ■ Before (April 12, 2004) and after (January 2, 2005) images of promontory south of Banda Aceh in northern Sumatra This point was able to deflect incoming waves, but enormous tracts of low lying coastal valleys behind it were devastated#14UMR Enlargements of before and after images of Sumatran coast near Gleebruk Village, south of Banda Aceh. Note how wave runup zone mimics the tree line, suggesting past tsunamis have wrought similar patterns of devasatation#15Coastal promontory in Meluaboh, in northern Sumatra, before tsunami (at left, taken on May 18, 2004) and after the tsunami (at right, taken on January 7, 2005) UMR#16Before tsunami on January 1, 2004 Surf begins to pull back from coastline Four views of shoreline in Kaulutara on the western coast of Sri Lanka, upper right and lower two imaged by satellite during the tsunami on 12-26-04. UMR#17Before tsunami on January 1, 2004 During tsunami wave flood surge During turbulent ebb flow back out to sea UMR Macro turbidity caused by ebb flow scour Additional images of Kaulutara, Sri Lanka imaged during the tsunami#1830 כי I INDIAN OCE AN YANMAR BURNA EURASIA PLATE Andaman Islands BURMA MICROPLATE INDIA PLATE CH - П 50 100 ཀན་བཀངའནཔར་ད ANDAMAN SEA SUNDA PLATE THAILAN 100 - Main Shock EXPLANATION 26 December 2004 Aftershocks through 29 Jan 2005 0 40-4.9 O 50-5.9 60-6.9 070-7.9 A Volcano es Faults (after Pubellier and others, 2004) Thrust ― Normal Strike-Slip Other 5 Strait of Malacos JOSUMATRA SCALE 111.com Muca Pig don 200 INDO Kalam μm Aftershocks of the M 9.0 Sumatra-Andaman Islands Earthquake of Dec 26, 2004 There have been 13 aftershocks of Magnitude > 6.0 since the main shock. The zone of aftershocks is over 1300 km long. Because aftershocks occur on and very near the fault planes of main shocks, the length of the aftershock zone suggests that main-shock fault-rupture may have extended north of epicenter by an amount significantly larger than 500 km. ■ However, a great earthquake may also trigger earthquake activity on faults that are distinct from the main-shock fault plane and separated from it by tens or even hundreds of kilometers. UMR#19UMR 5th largest earthquake ever recorded The earthquake of Dec.26th 2004 was the fifth largest in the world since 1900. The other four earthquakes that were larger are: ■ 1. 1960 May 22, Southern Chile, M=9.5 ■ 2. 1964 March 28, Prince William Sound, Alaska, M=9.2 ■ 3. 1957 March 9, Andreanoff Islands Alaska, M-9.1 4. 1952 Nov 4, Kamchatka M-9.0 5. 2004 Dec 26, Off west coast of Northern Sumatra, M=9.0. This magnitude may be upgraded to 9.3, based on studies now underway.#20Deadliest Earthquakes ■ 1. 1556 Jan 23, Senshi, China, 830,000 casualties (M=~8.0) ■ 2. 2004 Dec 26, Off west coast of N-Sumatra, ■ 3. ■ 4. ■ 5. 6. between 228,000 and 310,000 casualties (M=9.0) 1976 July 27, Tangshan, China, 255,000 casualties (M=7.5) 1780 Feb 28, Iran, 200,000 casualties (M=?) 1920 Dec 16, China, Gansu, 200,000 casualties (M=8.6) 1927 May 22, Tsinghai, China, 200,000 casualties (M=7.9) 7. 1923 Sept 1, Japan Kanto (Tokyo fire), 143,000 casualties (M=7.9) ■ 8. 1948 Oct 5, Ashgabat, Turkmenistan, 110,000 casualties (M=7.3) UMR#21Northern Sumatra Earthquake of 28 March 2005 95° 100° Satun Songkhla, ANDAMAN SEA Perlis Perlis Pattani THAILAND YalaNarathiwat 105° 0° 2004 ceh Kedah Pulau Pinang SOUTH CHINA SEA Kelantan Terengganu- 5° Perak Sumatera Utara 2005 2005 Sumatera Utara 1861 MALAYSIA Pahang Selangor. Negeri Sembilan SINGAPORE Melaka Johor Singapore Singapore Riau EXPLANATION Main Shock 28 March 2005 Earthquakes 28 Mar – 8 Apr 2005 4.0-4.9 Ⓒ 5.0-5.9 6.0-6.9 Main Shock Sumatra Jambi SUNDA PLATE 26 December 2004 Rupture Zones Sumatera Selatan 1833 1861 Sumatera Barat. Sumatera Barat INDIAN OCEAN E Sumatera Selatan 1833 Bengkulu Trench 5° AUSTRALIA PLATE 95° 100° 2004 Aftershocks AN 2005 Aftershocks INDONESIA Lampung Jakarta Jawa Barat 105° 5º "How big was the largest aftershock? "Was anyone killed? Kilometers 0 50 100 200 300 400 ■ A Magnitude 8.7 aftershock occurred on Monday March 28, 2005. At least 1000 people killed, 300 injured and 300 buildings destroyed on Nias; 100 people killed, many injured and several buildings damaged on Simeulue; 200 people killed UMR in Kepulauan Banyak; all in Sumatra. Tsunami waves 2 m high#225° Northern Sumatra Earthquake of 28 March 2005 95° 100° Satun Songkhla, ANDAMAN SEA Penis Perlis Pattani THAILAND ValaNarathiwat 105° 0° 5° 2004 2005 2005 Sumatera Utara 1861 Kedah Pulau Pinang SOUTH CHINA SEA Kelantan Terengganu- 5° Perak Sumatera Utara MALAYSIA Pahang Selangor. Negeri Sembilan Melaka Johor SINGAPORE Singapore Singapore Sumatra Sumatera Barat Sumatera Barat Sunda Trench INDIAN OCEAN Riau EXPLANATION Main Shock * 28 March 2005 Earthquakes 28 Mar - 8 Apr 2005 4.0-4.9 Ⓒ 5.0-5.9 6.0-6.9 Main Shock 26 December 2004 SUNDA PLATE Rupture Zones Jambi 1833 Sumatera Selatan 1861 Sumatera Selatan 1833 Bengkulu 2004 Aftershocks AN 2005 Aftershocks INDONESIA Lampung 5° When was the last big one? ▪How often do they occur? 95° AUSTRALIA PLATE 100° Kilometers 0 50 100 200 300 400 Jakarta Jawa Barat 105° Prior to December 26th, the largest earthquake along the subduction zone from southern Sumatra to the Andaman Islands occurred in 2000 and had a magnitude of 7.9. A magnitude 8.4 earthquake occurred in 1797, a magnitude 8.5 in 1861 and a magnitude 8.7 in 1833. All three ruptured sections of the subduction zone to the south of the recent earthquake. Interestingly, the 1797 and 1833 quakes are believed to have ruptured roughly the same area with only 36 years separating the events. Paleoseismic evidence shows that great earthquakes or earthquake UMR couplets occur about every 230 years.#23UMR ESTABLISHING AN INTERNATIONAL WARNING NETWORK American politicians and United Nations representatives were quick in calling for establishment of an international tsunami warning network in Southeast Asia, similar to that operated by NOAA and USGS in the Pacific since the Hilo tsunami in 1946. ■ Can't we just make more wave detection buoys and stick them out there in the ocean?#24DEEP WATER TSUNAMI WAVE MONITORING SYSTEM WARNING CENTER VIA SATELLITE DATA SIGNAL ACOUSTIC DATA SIGNAL PRESSURE SENSOR DATA PROCESSING MODULE NOAA/PMEL UMR LITE INDEPENDENT 3 COMPONENT BROAD-BAND SEISMIC STATION NOAA wave form detection buoys Can't we just make more wave detection buoys and stick them out there in the ocean? Only 3 of the 5 buoys in Pacific Ocean were working because no funds for upkeep made available by Congress prior to 12-26-04 event#25Problems with Tsunami Warnings ■ The greatest number of casualties were in the near shore zone along the western coast of Northern Sumatra, within 20 minutes travel time of the initial tsunami waves ■ The preliminary quake magnitude was estimated at 6.6 because the initial rupture was of that scale. Problem was the rupture propagated 1300 km up the Sunda Trench People have to have training to know WHAT TO DO in the event of a tsunami warning. They have to have a contingency plan in place. A simple "broadband warning" will not save their lives unless they know where to evacuate immediately UMR