Review of Tsunami early warning system and coastal resilience with a focus on Indian Ocean

Purpose This paper aims to provide a general overview of the international Tsunami warning system mandated by the United Nations, particularly on cataloging past studies and a strategic focus in the Indian Ocean, particularly on the Bay of Bengal region. Design/methodology/approach Present research assimilates the secondary non-classified data on the Tsunami warning system installed in the Indian Ocean. Qualitative review and exploratory research methodology have been followed to provide a holistic profile of the Tsunami rarly warning system (TEWS) and its role in coastal resilience. Findings The study finds the need for strategic focus to expand and interlink regional early warning cooperation mechanisms and partnerships to enhance capacities through cooperation and international assistance and mobilize resources necessary to maintain the TEWS in the Indian Ocean region. The enhanced capacity of the TEWS certainly improves the resilience of Indian Ocean coastal communities and infrastructures. Originality/value The study is original research and useful for policy planning and regional cooperation on data interlinkages for effective TEWS in the Indian Ocean region.

KOERI’s Tsunami Warning System in the Eastern Mediterranean and Its Connected Seas: A Decade of Achievements and Challenges

A tsunami warning system providing services in the Eastern Mediterranean, Aegean, Marmara and Black Seas under the UNESCO Intergovernmental Oceanographic Commission (IOC)—Intergovernmental Coordination Group (ICG) for the Tsunami Early Warning and Mitigation System in the North-Eastern Atlantic, the Mediterranean and Connected Seas (NEAMTWS) framework was established in Turkey by the Kandilli Observatory and Earthquake Research Institute (KOERI) (Özel et al., 2011). KOERI’s Regional Earthquake and Tsunami Monitoring Center (RETMC) was established on the foundations of the legacy KOERI National Earthquake Monitoring Center (NEMC) by adding observation, analysis and operational capability related to tsunami early warnings after an extensive preparatory period during 2009 and 2011. The center initiated its test-mode 7/24 operational status as a national tsunami warning center in 2011, and after a one year period it became operational as a candidate tsunami warning center for NEAMTWS on 1 July 2012, together with CENALT (Centre d’Alerte aux Tsunamis—France) and followed by the NOA (National Observatory of Athens—Greece) on 28 August 2012, INGV (Instituto Nazionale di Geofisica e Vulcanologia—Italy) on 1 October 2014 and IPMA (Instituto Português do Mar e da Atmosfera—Portugal) on 1 February 2018, completing full coverage of the tsunami-prone regions monitored by NEAMTWS. In this paper, an overview of the progress and continuous improvement of KOERI’s tsunami early warning system will be presented, together with lessons learned from important tsunamigenic events, such as the 20 July 2017 Bodrum–Kos Mw 6.6 and 30 October 2020 Samos–Izmir Mw 6.9 earthquakes. Gaps preventing the completion of an effective tsunami warning cycle and areas for future improvement are also addressed.

Revisiting the ocean’s non-isostatic response to 5-day atmospheric loading: New results based on global bottom pressure records and numerical modeling

We use bottom pressure records from 59 sites of the global tsunami warning system to examine the non-isostatic response of the World Ocean to surface air pressure forcing within the 4 to 6-day band. It is within this narrow “5-day” band that sea level fluctuations strongly depart from the isostatic inverted barometer response. Numerical simulations of the observed bottom pressures were conducted using a two-dimensional Princeton Ocean Model forced at the upper boundary by two versions of the air pressure loading: (a) an analytical version having the form of the westward propagating, 5-day Rossby-Haurwitz air pressure mode; and (b) an observational version based on a 16-year record of global-scale atmospheric reanalysis data with a spatial resolution of 2.5°. Simulations from the two models – consisting of barotropic standing waves of millibar amplitudes and near uniform phases in the Pacific, Atlantic and Indian oceans – are in close agreement and closely reproduce the observed bottom pressures. The marked similarity of the outputs from the two models and the ability of both models to accurately reproduce the seafloor pressure records indicates a pronounced dynamic response of the World Ocean to non-stationary air pressure fields resembling the theoretical Rossby-Haurwitz air pressure mode.

Estimasi Ancaman Gempabumi dan Tsunami di Kabupaten Pidie Jaya Aceh untuk Mendukung Keamanan Nasional

[Estimation of The Threat of Earthquake and Tsunami in Pidie Jaya Regency to Support National Security]. Bencana merupakan suatu ancaman non-militer dan nyata yang dihadapi dunia saat ini. Bencana mengancam keselamatan masyarakat yang pada akhirnya mengancam keamanan nasional suatu negara, termasuk Indonesia. Ancaman nyata yang saat ini dirasakan oleh masyarakat Indonesia adalah peningkatan kejadian bencana yang dirasakan hampir diseluruh wilayah Indonesia. Kabupaten Pidie Jaya yang merupakan bagian dari Provinsi Aceh juga memiliki ancaman multi bencana seperti gempabumi dan tsunami. Gempabumi yang terjadi di Pidie Jaya disebabkan oleh aktivitas Sesar Pidie dengan arah bidang patahan mendatar atau strike-slipe. Selain itu, terdapat Zona Megathrust Sumatera dan Sesar Besar Sumatera yang berada di Provinsi Aceh dengan aktivitas kegempaan yang dapat berpotensi tsunami. Dalam penelitian ini dilakukan suatu simulasi tsunami dengan output wilayah-wilayah yang berpotensi tsunami berserta run up atau ketinggian air tsunami akibat gempa di Zona Megathrust Aceh-Andaman. Penelitian ini menggunakan metode kualitatif (deskriptif analisis) sebagai desain penelitian. Penelitian dilakukan pada 18 Maret 2021 di ruang operasional InaTEWS (Indonesia Tsunami Warning System) Badan Meteorologi, Klimatologi, dan Geofisika (BMKG) menggunakan bantuan software TOAST (Tsunami Observation and Simulation Terminal). Dari seluruh rangkaian pengolahan dan analisis data didapatkan hasil bahwa Zona Megathrust Aceh-Andaman berpotensi tsunami dengan run up (ketinggian air tsunami) yang paling tertinggi sebesar 10,5 meter di Meulaboh, Kab. Aceh Barat, 5,5 meter di Kota Sabang, dan 3 meter di Kabupaten Pidie Jaya dengan waktu tiba tsunami (golden time) sekitar 24 menit 55 detik. Kajian atas estimasi gempabumi dan tsunami ini dapat dijadikan sebagai sumber informasi dalam penentuan kebijakan BPBD Pidie Jaya dalam upaya mitigasi bencana untuk melindungi masyarakat Pidie Jaya dan mewujudkan keamanan nasional.

Tsunami risk management for crustal earthquakes and non-seismic sources in Italy

Destructive tsunamis are most often generated by large earthquakes occurring at subduction interfaces, but also other “atypical” sources—defined as crustal earthquakes and non-seismic sources altogether—may cause significant tsunami threats. Tsunamis may indeed be generated by different sources, such as earthquakes, submarine or coastal landslides, volcano-related phenomena, and atmospheric perturbations. The consideration of atypical sources is important worldwide, but it is especially prominent in complex tectonic settings such as the Mediterranean, the Caribbean, or the Indonesian archipelago. The recent disasters in Indonesia in 2018, caused by the Palu-Sulawesi magnitude Mw 7.5 crustal earthquake and by the collapse of the Anak-Krakatau volcano, recall the importance of such sources. Dealing with atypical sources represents a scientific, technical, and computational challenge, which depends on the capability of quantifying and managing uncertainty efficiently and of reducing it with accurate physical modelling. Here, we first introduce the general framework in which tsunami threats are treated, and then we review the current status and the expected future development of tsunami hazard quantifications and of the tsunami warning systems in Italy, with a specific focus on the treatment of atypical sources. In Italy, where the memory of historical atypical events like the 1908 Messina earthquake or the relatively recent 2002 Stromboli tsunami is still vivid, specific attention has been indeed dedicated to the progressive development of innovative strategies to deal with such atypical sources. More specifically, we review the (national) hazard analyses and their application for coastal planning, as well as the two operating tsunami warning systems: the national warning system for seismically generated tsunamis (SiAM), whose upstream component—the CAT-INGV—is also a Tsunami Service Provider of the North-eastern Atlantic, the Mediterranean and connected seas Tsunami Warning System (NEAMTWS) coordinated by the Intergovernmental Coordination Group established by the Intergovernmental Oceanographic Commission (IOC) of UNESCO, and the local warning system for tsunamis generated by volcanic slides along the Sciara del Fuoco of Stromboli volcano. Finally, we review the state of knowledge about other potential tsunami sources that may generate significant tsunamis for the Italian coasts, but that are not presently considered in existing tsunami warning systems. This may be considered the first step towards their inclusion in the national tsunami hazard and warning programs.

Introduction

Tsunamis affect people—that is why researchers study them and why the media tracks their paths of destruction. A devastating tsunami is usually an event that is so far beyond people’s life experiences that they often struggle to rationalize what they saw. The destruction that has been wrought on human communities over the millennia is reflected in stories passed down either through word of mouth or in the writings of experts and non-experts alike. With an unprecedented wealth of previously unpublished tsunami survivor stories, the Introduction outlines the human side of these catastrophic events and what they mean to people. The basics of the tsunami warning system are introduced, as are some of the cases discussed in the book.

The Case of the Disappearing Lighthouse

This chapter follows the course of the waves caused by the 1946 Aleutian earthquake, which ultimately resulted in the creation of the first official tsunami warning system, from their source in Alaska as they demolished a Coast Guard lighthouse, caused massive destruction and loss of life in Hawaii, and ultimately reached the shores of Antarctica. The chapter presents observations by mariners at sea off Alaska, Navy pilots flying over Hawaii, and a marine geologist in the Hawaiian Islands for the Bikini atomic bomb tests and firsthand accounts of amazing survival and tragic loss in Hawaii. In addition to the devastating tsunami, 1946 marked the year when scientists in Japan and the English-speaking world finally adopted the name “tsunami” for these events.

Boxing Day

It had been well over 100 years since a major tsunami had struck the Indian Ocean, an event lost from living memory. The world’s only tsunami warning system operated exclusively in the Pacific Ocean, leaving the Indian Ocean neglected. On the day after Christmas 2004, a major earthquake struck off the coast of Indonesia, creating a tsunami that would ultimately leave more than 230,000 dead. The tsunami waves would spread across the Indian Ocean, causing massive death and destruction in Thailand, India, Sri Lanka, the Maldives, and even along the east coast of Africa. This chapter presents survivor stories to add a unique perspective to this devastating event. The Indian Ocean now has a tsunami warning system, but it is being seriously neglected. What that portends no one yet knows.

KAJIAN KAWASAN PERMUKIMAN PESISIR BERBASIS MITIGASI BENCANA GUNUNG BERAPI BAWAH LAUT MAHANGETANG (Studi Kasus Desa Lapango, Kecamatan Manganitu Selatan Kabupaten Kepulauan Sangihe)

Lapango Village is one of the villages in the Sangihe Islands Regency where the settlement is located in a coastal area, precisely in South Manganitu District. The geographical condition of this village is one of the areas close to the Mahangetang Underwater Volcano. From this geographical condition, it is necessary to study the Planning and Spatial Planning of Settlement Areas which are carried out by taking into account the physical conditions of geographic areas that are prone to disasters, especially submarine volcanic disasters, so they must be based on disaster mitigation. The purpose of this research is to obtain a study according to the zoning pattern of community settlements based on Disaster Mitigation. The method used in this research is descriptive quantitative and qualitative, data collection was carried out using a questionnaire to measure Respondents' Perceptions of Disaster Preparedness whose variables and indicators were measured based on Knowledge and Attitudes (PS), Policies, Regulations, and Guidelines (KPP). , Plan for Emergency Situation (RKD), Tsunami Warning System (SPB), Ability to Mobilize Resources (MSD), Next identify the geographical condition of the settlement in coastal areas and the human population inhabiting these settlements. From this data, analysis is made with a GIS (Geographic Information System) and then followed by a study and concept of zoning for disaster-prone areas and providing information and recommendations to governments and communities in coastal areas in an effort to reduce disaster risk by including Disaster Hazard Map activities ( PRB) into the RPJM for the South Manganitu District, especially for Lapango VillageKeywords: Coastal Areas, Mitigation, Disasters, Lapango Village Abstrak: Desa Lapango merupakan salah satu desa yang berada di Kabupaten Kepulauan Sangihe kedudukan pemukimannya berada di wilayah pesisir tepatnya di Kecamatan Manganitu Selatan. Kondisi geografi dari desa ini merupakan salah satu daerah berdekatan dengan Gunung Api Bawah Laut Mahangetang. Dari kondisi geografis tersebut, maka diperlukan kajian untuk Perencanaan dan Penataan Ruang Kawasan Permukiman yang diselenggarakan dengan memperhatikan kondisi fisik wilayah geografis yang rentan bencana khususnya bencana gunung api bawah laut, sehingga harus berbasis mitigasi bencana. Tujuan dari penelitian ini untuk mendapatkan kajian menurut pola zonasi permukiman masyarakat berbasis Mitigasi Bencana. Metode yang digunakan dalam penelitian ini adalah deskriptif kuantitatif dan kualitatif, pengumpulan data dilakukan dengan menggunakan kuesioner untuk mengukur Persepsi Responden Mengenai Kesiapsiagaan dalam menghadapi bencana yang variabel dan indikatornya diukur berdasarkan, Pengetahuan dan Sikap (PS), Kebijakan, Peraturan, dan Panduan (KPP), Rencana Untuk Keadaan Darurat (RKD), Sistem Peringatan Bencana Tsunami (SPB), Kemampuan Memobilisasi Sumber Daya (MSD), Selanjutnya mengidentifikasi keadaan geografis dari permukiman wilayah pesisir dan populasi manusia yang mendiami permukiman tersebut.Dari data tersebut dibuat analisis dengan GIS (Geographic Information System) kemudian dilanjutkan dengan dibuat kajian dan konsep zonasi wilayah yang rawan bencana serta memberikan informasi serta rekomendasi kepada pemerintah dan masyarakat yang berada dikawasan pesisir dalam upaya mengurangi risiko bencana adalah dengan memasukkan kegiatan Peta Rawan Bencana (PRB) ke dalam RPJM Kecamatan Manganitu Selatan terlebih Khusus Desa Lapango.Kata Kunci: Wilayah Pesisir, Mitigasi, Bencana, Desa Lapango

Determination of tsunami run-up and golden time in the megathrust subduction zone of the sunda strait segment

The Indonesian Disaster Data and Information Management Database state that the tsunami in the Megathrust Subduction Zone of the Sunda Strait Segment is a disaster threat with high impact and loss of life every time it occurs. Therefore, determining the run-up and golden time of the tsunami in the Megathrust Subduction Zone of the Sunda Strait Segment is necessary as part of the mitigation of seismic activity that has the potential for a tsunami. The design of this study is qualitative research with primary data to determine the run-up and golden time of the tsunami in the Megathrust Subduction Zone of the Sunda Strait Segment obtained from the Indonesia Tsunami Warning System (InaTEWS) at BMKG. The results of the study inform that seismic activity in the Megathrust Subduction Zone of the Sunda Strait Segment can cause a tsunami with a run-up of 5.99 meters and a golden time of 40 minutes 19 seconds in Banten and South Lampung, the run-up of 3.83 meters, and a golden time of 1 hour 1 minute 10 seconds in Pacitan, East Java, run up 3.28 meters and golden time 33 minutes 15 seconds in Pangandaran, West Java.