International Press & Media
                                              Briefing

                                     Wednesday 9 February 2005

                                             Welcome to
                                         The United Kingdom
                                        Hydrographic Office

                                          Dr Wyn Williams
                                              CE UKHO

                                            Introduction

                                       Captain Ian Turner RN
                                      Hydrographer of the Navy

                                             HMS SCOTT

                                   Hydrographic Instruction 1123

                                           BAY OF BENGAL

                                      EARTHQUAKE RUPTURE ZONE

                                             HMS Scott

                                             HMS SCOTT
                                                  
                                     Hydrographic Survey Vessel

                                     Commander Steve Malcolm RN
                                         Commanding Officer

                                            Outline Plan

•            Why did we need the survey?

•            Why this ship?

•            Capability – Equipment and People

•            Operational Environment

•            Co-operation

•            Survey Results

•            What next?

•            Questions and Panel Discussion



                                    Why did we need the survey?

                                        Existing Chart Data



                                         Channel and ridge

                                           Why HMS SCOTT?

                                      Equipment and Capability





                                           Why HMS SCOTT?

                                             Personnel





                                            Co-operation

•            Government Agencies (FCO, MoD)

•            Military, Scientific and Academic institutions (RN, BGS and SOC)

•            Indonesian authorities





                                              Results

•            Background to the December 26 earthquake

  –       Plate tectonic setting and structure of subduction zones

  –       Seismology

  –       Tsunami generation and observations

•            General survey plan, area covered and overview of results so far

•            Active tectonic features

•            Active erosion/sedimentary features

                                         Why did it happen?

•            Indian plate is being subducted beneath Eurasia / Burma plate

•            Rate 50-60mm/yr but very oblique

•            Two large earthquakes during C19^th further to south (Figure from studies by Kerry
Sieh, CalTech)

                                         Generic subduction
                                         zone cross section

                                        Earthquake-generated
                                              tsunamis

•            Seafloor deformed by earthquake

•            Wave initiated with small amplitude and high speed in deep water

•            Speed decreases and amplitude increases in shallow water

                                            Survey Area

                                             Lines Run

                                             OVERLAY OF
                                           DATA COLLECTED
                                         AND CURRENT CHART

                                       Examples of Landslide 
                                               Scars

                                          Slide Scars and
                                           Thrust Faults

                                           Plate Boundary

                                           Youthful Slide
                                         with Slide Blocks

                                             Example of
                                             Slide Scar

                                        Diversion of Canyon

                                       Area of Active Erosion

                                     Older slide on newer ridge

                                           Large bedforms

                                                   Thank you

                                                  Questions?

                                             HMS Scott