tsunami workshop, santiago de chile, 29-30 sep. 2005 tsunami warning and tsunami hazard mitigation...

Tsunami Workshop, Santiago de Chile, 29-30 sep. 2005

Tsunami Warning and Tsunami Hazard Mitigation Efforts in Nicaragua

Wilfried Strauch, INETER, Managua

http://www.ineter.gob.ni/geofisica/tsunami/tsunami.html

- Tsunami causes

- Tsunami hazard estimation

- Warning system


Tsunami en los 1990


Nicaragua 1992

- Tsunami earthquakeMw=7.6- Very low seismic effect- No warning> 170 killed


1992

• No knowledge about tsunami hazard

• No seismic network

• No communications system

• No tsunami warning system

• No trained personnel

• No educated population


Actions of INETER after 1992• Sept. 1992: of seismic monitoring, service 24x7 • 1993: Integration into PTWS, ITSU• Development seismic network

(1992:2 estaciones, 2005: 61 estaciones)• Development of Monitoring and Early Warning center• Development Information&Communications del Systems• Execution of projects on tsunami hazard• Development of sea gauge network• Pushing a Regional Warning System in CA • 2005 Seismic broad band network, Small seismic array, • 2005 Facilities for immediate information to population


Tsunami sources in Nicaragua


Tsunami Catalogue1500-2002 – 49 tsunamis in Central America 5 affected Nicaragua

1 desastrous en Nicaragua (1992)

Sources: Morales, 1992-2005; Molina, 1994, Fernández et al, 1999


Funding

• After 1992 tsunami little interest of funding agencies (“low probability for another tsunami”)

• Participation of INETER in research projects• Additional funding by Nicaraguan goverment –

financial source for development of seismic monitoring and Tsunami warning system


Basic research on Tectonics, structure, etc• After the 1992 tsunami – deeper earthquake and tsunami knowledge

for Nicaragua and CA due to a large number of research work and projects on subduction processes, tectonics, geology, volcanology, seismic source mechanisms, tsunami generation, ..

Especially:• NSF funded “Subduction factory”• DFG/Germany funded “Special research area”

• E.g. 2005 – temporary broad band network for crustal structure and seismicity studies. Nicaragua & Costa Rica. 46 stations .

With Boston Univ. & Brown Univ.


Tsunami due to submarine landslide

Shaded relief map of multibeam bathymetry data showing the Jaco scarp produced by seamount subduction offshore Costa Rica. A faulted block occurs downslope ofthe main scarp, which seems to indicate that detached blocks creep along headwall faults without loosing their coherent structure. However, a slumped mass at the base of the headwall scarp indicates that blocks may eventually fail catastrophically. Ranero & Weinrebe, 2004

Source: GEOMAR, 2004


Lake Managua: Tsunamis caused by volcanic explosion

Sources: Volcanic hazards in Nicaragua: Past, present, and future. A.Freundt, St.Kutterolf, H.-U.Schmincke, T.Hansteen, H.Wehrmann,W. Perez,, W. Strauch, Navarro, in preparaciónTsunami in Lake Managua, Nicaragua, triggered by a compositionally zoned plinian eruption, A. Freundt, St. Kutterolf, H. Wehrmann, H-U. Schmincke, W.Strauch,Conference, IAVCEI, Chile, 2004

Source of volcanic explosion which generated tsunami

Sampling points

Max. Height of waves :20 m

When?Aprox 2000 years ago

Foto: Section of Mateare in the low area Oeste de la West of Chiltepe peninsula.

Unit A A, fallout, product of discontinuous plinian activity

2)Mateare sand (MS) deposited by the tsunami,and

3) Unit B – massive fallout of pommes of the stable plinian phase of the eruption..


Lake Nicaragua: Tsunami by volcano collapse ?Mombacho volcano:Prehistorical collapse. No evidences yet for ocurrence of tsunami.

Other possible sites:Momotombo volcanoConcepción volcano.

In process: Study on possible tsunami generation and propagation in Lake Nicaragua.

Mombacho Volcano1200 m

Isletas

Granadacity

Apoyo Caldera

Landslide,Collapse

Tsunami!?

5 km

Source: INETER-NGI-Project


Tsunami hazard estimation


Identification of high risk areas, “hot spots”

Height -> “Hazard”10 - 20 m low 5 - 10 m high < 5 m very highvery high

Corinto

Population density

Landscan 2004

Source:Strauch, 2005


Corinto “Hot spot”

Corinto

Population:

Aprox. 10,000

Height: 4 msnm.

Evacuation route10-15 km !???

Save place


Inundation maps based on numerical simulation, Pacific coast

(to be finished December 2005)

• Recollection of existing bathymetric data• Bathymetric mapping of Masachapa area• Digital elevation model of the coastal strip• Seismic source mechanism, 1992 tsunami

earthquake• Numerical simulation of tsunami generation

and propagation (TIME)• Inundation maps

Source: INETER-JICA-Project


Corinto

San Juan del SurPuerto Sandino

Study areas – most populated places

Masachapa

Bathymetry

Source: INETER-JICA-Project, 2004-06


Pilot Project: Tsunami disaster prevention in Masachapa area

Source: INETER-COSUDE Project, 2005-06

-Information and education

-Local hazard map;

-Save places, evacuation routes

-Tsunami signs

-Prevention measures for schools

-Installation of sirens

-Participation of local administration and population


Alert System


Alert system: Local tsunami

-Magnitud: > 7.0

-Location: Nicaraguan Pacific Ocean


Local Tsunami – Alert System

*Earthquake->Tsunami

Seismic recording

Civil Defense – to local administrations, 10 min

Evacuation

wave arrives in 45 minutes!

Analysis – Seismic data centerAutomatic procedures:-Broad band sensor-Small seismic array-Virtual regional network

Radio, TV stations – to population, 2 min

Cellular phone –to local population, 2 min

10 min ?human factor

3 min


Chinandega (El viejo)

1.- Venecia2.- Aposentillo3.- Jiquilillo4.- Aserraderos5.- Los Zorros6.- Padre Ramos7.- Mechapa8.- Punta Nata9.- Potosí

Chinandega (Corinto)

10.- Corinto11.- Isla del Cardón12.- Isla del Amor

Chinandega (El Realejo)

13.- Isla Maderas Negras14.- Isla Paredones15.- Paso Caballos

León

16.- El Tránsito 17.- Puerto Sandino18.- Salinas Grandes19.- Poneloya20.- Las Peñitas21.- Los Brasiles

Managua

22.- Salamina23.- Montelimar24.- Masachapa25.- Pochomil26.- San Diego27.- Gran Pacífica28.- Miraflores

Carazo

29.- Casares30.- La Boquita31.- Bocana de Masapa

Jinotepe

32.- Tipilapa33.- Huehuete34.- La Bocana

Rivas

35.- El Ostional36.- San Juan del Sur37.- El Menco38.- El Gigante39.- San Martín40.- Las Salinas41.- El Astillero42.- La Flor

(130,000) under risk

INETERINETER

CODECODE

DEFENSA CIVILDEFENSA CIVIL

90 kms

45 min

1

34

3837

23

4

65

87

9

1011

1213

14

15

16

17

18

19

202122

2324

2526

2728

2930

3132

33

3536

39

404142

Civil Defense Communications SystemSource Defensa Civil, 2005


-Alert messenger to PC screen of radio/TV presenters (under testing)

-SMS cell phone to decision maker (under testing)

-SMS cell phone to large sectors of population (under development)

New communication methods(in development)


Thank you !


Towards a Regional Tsunami Warning System in Central America

Wilfried Strauch, INETER, Managua

with support from:

CEPREDENAC

INSIVUMEH – Guatemala;

SNET- El Salvador;

OVSICORI, UCR, CASC-Costa Rica;

UPA- Panama;

COPECO-Honduras.


“Hot Spots” Tsunami CA

Corinto

PanamáPuerto Armuelles

Puntarenas

El Triunfo

Boca del Toro

Bilwi

El Bluff/BluefieldsSan Carlos

- Low profile of the coast; -high population concentration

Hight -> “Hazard”10 - 20 m low 5 - 10 m high < 5 m very highvery high

Colón


Regional program for a tsunami warning system in Central America• Proposal of INETER (2003) to CEPREDENAC, based on experience in Nicaragua

• Adopted in 2005

• Creation of national warning systems• Every national WS obtains data from all other countries, in

real time• Every national WS transmits its warning messages to all other

countries• A variety of technical communications measures are tobe used• A very redundant system


The 2004 Tsunami in South Asia stimulated:

• Actions of CEPREDENAC (Regional Center for Disaster Prevention)

• Tsunami hazard studies and education measures in Costa Rica

• Interest of Emergency Commissions in all CA countries

• Meetings of the relevant institutions of all CA countries

• More interest of funding agencies


Activities in CA towards a Tsunami Warning System, 2005

- Meeting of body of Directors of CEPREDENAC,Kobe, Decision about a strategic meeting

- Strategic meeting on Tsunami WS, in San Salvador, - Decision on program Regional Tsunami WS

- Tsunami Workshop, 25-27Abril, Managua

Presentation of immediate actions and project profiles

- Workshop on digital seismic data acquisition and processing

Training for data seismic data exchange and virtual networks


National Warning Centers

• Consider the threat of local tsunamis: The local tsunami threat is more efficient using the national capacities of seismic and hidrografic monitoring and using local communications methods to the population.

• Independent alert for regional eventss : For the detection of a potentional regional threat a single seismic station can be sufficient (e.g. with TREMORS software).

• Interpretation of the messages of PTWC : It is national responsability to interprete the inforemation or warning messages of PTWC and to decide how to act on them.

• Dissemination of alert messages: Only the national centers can cooperate efficiently with national and local authorities to make sure that the warning messages are distribute rapidly to the areas under risk and to establish evacuation plans.


Alert system- Formation of a technical steering committee- Formation of National Warning Centers- Integration in PTWS of all CA countries (missing: Panama, Honduras)- Elaboration of national communications plans, preliminary

Monitoring and communications network - Exchange of seismic data in real time, virtual seismic networks

Projects- Elaboration of project proposals for long an medium term development

Immediate actions, planned for 2005


Possibles Projects

Monitoreo y Alerta.Improvement/installation of a seismic broad band network, satelital. Installation of a sea gauges, including off shore. Information on alternative tsunami detection methodsHazard mapping. Hazard mapping, tsunami simulation, inundation maps. “Hot spot” = population centers under high risk. Factibility studies on special protection measures for “Hot Spots”. Studies of tsunami causes – earthquakes, volc.explosiones, submarine slidesInformación y Educación. Alternative measures for information and education of population


Muchas Gracias!

tsunami workshop, santiago de chile, 29-30 sep. 2005 tsunami warning and tsunami hazard mitigation...

Documents

tsunami workshop

tsunami sources

tsunami knowledge

tsunami little

tsunami generation

tsunami earthquakemw

tsunami catalogue

tsunami warning system