scholarly journals The GITEWS ocean bottom sensor packages

2010 ◽  
Vol 10 (8) ◽  
pp. 1759-1780
Author(s):  
O. Boebel ◽  
M. Busack ◽  
E. R. Flueh ◽  
V. Gouretski ◽  
H. Rohr ◽  
...  

Abstract. The German-Indonesian Tsunami Early Warning System (GITEWS) aims at reducing the risks posed by events such as the 26 December 2004 Indian Ocean tsunami. To minimize the lead time for tsunami alerts, to avoid false alarms, and to accurately predict tsunami wave heights, real-time observations of ocean bottom pressure from the deep ocean are required. As part of the GITEWS infrastructure, the parallel development of two ocean bottom sensor packages, PACT (Pressure based Acoustically Coupled Tsunameter) and OBU (Ocean Bottom Unit), was initiated. The sensor package requirements included bidirectional acoustic links between the bottom sensor packages and the hosting surface buoys, which are moored nearby. Furthermore, compatibility between these sensor systems and the overall GITEWS data-flow structure and command hierarchy was mandatory. While PACT aims at providing highly reliable, long term bottom pressure data only, OBU is based on ocean bottom seismometers to concurrently record sea-floor motion, necessitating highest data rates. This paper presents the technical design of PACT, OBU and the HydroAcoustic Modem (HAM.node) which is used by both systems, along with first results from instrument deployments off Indonesia.

2011 ◽  
Vol 11 (3) ◽  
pp. 741-749 ◽  
Author(s):  
T. Schöne ◽  
W. Pandoe ◽  
I. Mudita ◽  
S. Roemer ◽  
J. Illigner ◽  
...  

Abstract. On Boxing Day 2004, a severe tsunami was generated by a strong earthquake in Northern Sumatra causing a large number of casualties. At this time, neither an offshore buoy network was in place to measure tsunami waves, nor a system to disseminate tsunami warnings to local governmental entities. Since then, buoys have been developed by Indonesia and Germany, complemented by NOAA's Deep-ocean Assessment and Reporting of Tsunamis (DART) buoys, and have been moored offshore Sumatra and Java. The suite of sensors for offshore tsunami detection in Indonesia has been advanced by adding GPS technology for water level measurements. The usage of GPS buoys in tsunami warning systems is a relatively new approach. The concept of the German Indonesian Tsunami Early Warning System (GITEWS) (Rudloff et al., 2009) combines GPS technology and ocean bottom pressure (OBP) measurements. Especially for near-field installations where the seismic noise may deteriorate the OBP data, GPS-derived sea level heights provide additional information. The GPS buoy technology is precise enough to detect medium to large tsunamis of amplitudes larger than 10 cm. The analysis presented here suggests that for about 68% of the time, tsunamis larger than 5 cm may be detectable.


Ingenius ◽  
2017 ◽  
pp. 84
Author(s):  
Freddy Walter Villao Quezada

<p>El terremoto de Ecuador ocurrido el 16 de abril de 2016, con una magnitud de 7.8, generó un pequeño tsunami local, evento registrado claramente por el sistema de boyas DART (Deep-ocean Assessment and Reporting of Tsunamis), el cual le tomó menos de diez minutos en arribar a las costas de Esmeraldas. Ecuador tiene el riesgo de un tsunami de gran magnitud cerca de su costa. Bajo el escenario de un tsunami cerca de la costa ecuatoriana, un sistema de alerta temprana de tsunami para alertar a las ciudades costeras vulnerables basado en las lecturas de las boyas de tsunami localizadas en aguas ecuatorianas es mandatorio. Este artículo describe el diseño de un sistema de alerta temprana para la costa ecuatoriana basado en terminales satelitales de ráfaga corta instalados en las boyas de tsunami cerca de la costa ecuatoriana y sirenas de alerta temprana localizadas en ciudades costeras. El sistema propuesto instalado en las boyas de tsunami tiene acceso a las lecturas del BPR (Bottom Pressure Recorder). En caso de un evento de tsunami registrado por el BPR, el sistema automáticamente envía una trama de datos para activar las sirenas de alerta temprana en las ciudades costeras. El sistema propuesto se basa en microcontroladores de bajo costo con código abierto y paneles solares con ultracapacitores como unidad de almacenamiento de energía para asegurar larga duración sin mantenimiento significativo. Basados en las pruebas de campo, este diseño para un sistema de alerta temprana de tsunami totalmente autónomo resultó apropiado para proteger a la población de las ciudades costeras ecuatorianas.</p>


2020 ◽  
Author(s):  
Harsh Gupta

&lt;p&gt;The 26 December 2004 Sumatra earthquake of Mw 9.2 and the resultant tsunami that claimed over 2,50,000 human lives is probably the most destructive natural disaster of the 21&lt;sup&gt;st&lt;/sup&gt; Century so far. Although the science of tsunami warning had advanced sufficiently by that time, with several tsunami warning centers operating in various oceans, no such system existed for the Indian Ocean. Here we present the discussions and interactions held in India and globally to convince setting up of ITEWS. False tsunami alarms subsequent to 26 December 2004 earthquake had developed a sense of scientific disbelief in the public and to a certain extent in Government of India. We demonstrated to the national and international community that there are only two stretches of faults that could host tsunamigenic earthquakes as far as the India Ocean is concerned. These are: 1) a stretch of some 4000 km of a fault segment extending from Sumatra to Andaman Islands and 2) an area of about 500 km radius off the Makaran Coast in the Arabian Sea. And if we cover these two areas with ocean bottom pressure recorders, the problem of false alarms would be reduced to a large- extant. This plan was finally agreed to and necessary financial, logistic and technical support was made available. The setting up of the ITEWS started in middle 2005 and was completed in August 2007. It has performed very efficiently since then. Over the past ~ 8 years, it monitored ~ 500 M &amp;#8805; 6.5 and provided advisories. As against the requirement placed by IOC of issuing an advisory in 10 to 15 minutes time, ITEWS has been doing it in ~ 8 minutes. Since its inception in 2007, no false alarm has been issued and it is rated among the best in the world.&lt;/p&gt;&lt;p&gt;IOC has designated ITEWS as the Regional Tsunami advisory Provider (TSP) Indian Ocean Regional Tsunami Center.&lt;/p&gt;


2011 ◽  
Vol 32 (4) ◽  
pp. 375-392 ◽  
Author(s):  
Marek Grad ◽  
Rolf Mjelde ◽  
Wojciech Czuba ◽  
Aleksander Guterch ◽  
Johannes Schweitzer ◽  
...  

Modelling of seafloor multiples observed in OBS data from the North Atlantic - new seismic tool for oceanography?In marine seismic wide-angle profiling the recorded wave field is dominated by waves propagating in the water. These strong direct and multiple water waves are generally treated as noise, and considerable processing efforts are employed in order minimize their influences. In this paper we demonstrate how the water arrivals can be used to determine the water velocity beneath the seismic wide-angle profile acquired in the Northern Atlantic. The pattern of water multiples generated by air-guns and recorded by Ocean Bottom Seismometers (OBS) changes with ocean depth and allows determination of 2D model of velocity. Along the profile, the water velocity is found to change from about 1450 to approximately 1490 m/s. In the uppermost 400 m the velocities are in the range of 1455-1475 m/s, corresponding to the oceanic thermocline. In the deep ocean there is a velocity decrease with depth, and a minimum velocity of about 1450 m/s is reached at about 1.5 km depth. Below that, the velocity increases to about 1495 m/s at approximately 2.5 km depth. Our model compares well with estimates from CTD (Conductivity, Temperature, Depth) data collected nearby, suggesting that the modelling of water multiples from OBS data might become an important oceanographic tool.


2008 ◽  
Vol 02 (03) ◽  
pp. 197-226 ◽  
Author(s):  
B. PRASAD KUMAR ◽  
R. RAJESH KUMAR ◽  
S. K. DUBE ◽  
A. D. RAO ◽  
TAD MURTY ◽  
...  

On 26th December 2004, the countries within the vicinity of East Indian Ocean experienced the most devastating tsunami in recorded history. This tsunami was triggered by an earthquake of magnitude 9.0 on the Richter scale at 3.4°N, 95.7°E off the coast of Sumatra in the Indonesian Archipelago at 06:29 hrs IST (00:59 hrs GMT). One of the most basic information that any tsunami warning center should have at its disposal, is information on Tsunami Travel Times (TTT) to various coastal locations surrounding the Indian Ocean rim, as well as to several island locations. Devoid of this information, no ETA's (expected times of arrival) can be included in the real-time tsunami warnings. The work describes on development of a comprehensive TTT atlas providing ETA's to various coastal destinations in the Indian Ocean rim. This Atlas was first released on the first anniversary of the Indian Ocean Tsunami and was dedicated to the victims. Application of soft computing tools like Artificial Neural Network (ANN) for prediction of ETA can be immensely useful in a real-time mode. The major advantage of using ANN in a real-time tsunami travel time prediction is its high merit in producing ETA at a much faster time and also simultaneously preserving the consistency of prediction. Overall, it can be mentioned that modern technology can prevent or help in minimizing the loss of life and property provided we integrate all essential components in the warning system and put it to the best possible use.


2020 ◽  
Vol 11 (2) ◽  
Author(s):  
Bachtiar W. Mutaqin ◽  
Ikhwan Amri ◽  
Bagas Aditya

Indonesia memiliki catatan sejarah yang panjang dengan bencana tsunami. Dari sejumlah kejadian tsunami yang ada, tsunami Samudra Hindia tahun 2004 dinilai sebagai bencana alam yang paling mematikan sepanjang abad dan paling berperan dalam mengubah paradigma manajemen kebencanaan di Indonesia. Penelitian ini bertujuan untuk meninjau pola kejadian tsunami dan perkembangan manajemen bencana di Indonesia setelah tsunami tahun 2004 dengan memanfaatkan database tsunami dan tinjauan literatur. Sebanyak 22 kejadian tsunami telah tercatat di Indonesia selama 2005-2018, di mana sebagian besar lokasi tsunami terkonsentrasi di Pulau Sumatera bagian barat dan bersumber dari Samudra Hindia. Tujuh kejadian diantaranya menimbulkan dampak signifikan, termasuk dua tsunami terakhir yang dipicu oleh faktor non seismik. Sistem manajemen bencana sebenarnya telah mengalami perubahan secara besar-besaran setelah tsunami tahun 2004, mulai dari berlakunya peraturan perundang-undangan tentang penanggulangan bencana, pembentukan institusi baru untuk penanggulangan bencana, hingga konstuksi sistem peringatan dini tsunami (InaTEWS). Meskipun telah berfokus pada upaya preventif, dampak tsunami dalam beberapa tahun terakhir masih cukup besar. Hal ini dipengaruhi oleh 4 faktor utama: (1) konsentrasi penduduk yang tinggi di area bahaya tsunami, (2) terbatasnya infrastruktur diseminasi peringatan dini, (3) kurangnya kesadaran masyarakat untuk melakukan evakuasi mandiri tanpa menunggu peringatan, dan (4) sistem peringatan dini tsunami belum mempertimbangkan faktor non seismik.Indonesia has a long history with the tsunami. From numerous tsunami events in the world, the 2004 Indian Ocean tsunami was considered as the deadliest natural disaster of the century and had the most role in changing the paradigm of disaster management in Indonesia. This study aims to review the spatial pattern of tsunami events and the development of disaster management in Indonesia following the 2004 tsunami through the tsunami database and literature review. At least there are 22 tsunami events were recorded in Indonesia in the period of 2005-2018, where most of its locations were concentrated on the western part of Sumatra Island and sourced from the Indian Ocean. We had identified that seven of these events have significant impacts, including the last two tsunamis triggered by non-seismic factors. The disaster management system has actually improved drastically following the 2004 tsunami, such as the enactment of laws and regulations on disaster management, the establishment of special institutions for disaster management, and the construction of a tsunami early warning system (InaTEWS). Although it has focused on preventive measures, tsunami impacts in recent years are still quite large. This situation is affected by four factors: (1) high and dense population in the tsunami hazard area, (2) limited infrastructure for early warning dissemination, (3) lack of public awareness to conduct evacuations following the disaster events, and (4) early warning systems for tsunami has not considered yet the non-seismic factors.


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