# Presentation: 567832

## Northwest Pacific Tsunami Advisory Center

- Japan Meteorological Agency

## Northwest Pacific Tsunami Advisory Center

**Global**
**Seismic**
**Network**

**Countries in Northwest Pacific Ocean**

**Japanese**
**Seismic**
**Network**

- Pacific Tsunami Warning
-  Center (PTWC)

- Information Exchange
-  - Magnitude
-  - Hypocenter
-  - Tsunami Information

*Analysis of seismic data and estimation of arrival time and height of tsunami generated by earthquakes in the Northwest Pacific Area*

**JMA Headquarters**

**Northwest Pacific Tsunami Advisory**

- - Origin Time
- - Hypocenter
- - Magnitude  (>=6.5)
- - Estimated arrival time and height of tsunami

- Through  the Global Telecommunication System of WMO, E-mail and/or Facsimile

**Notes:**
Discussion about establishment of a regional center in the Northwest Pacific region has been made in past ITSU meetings
JMA started operation of the Northwest Pacific Tsunami Advisory Center this March. This Center was a established as a regional center in the Northwest Pacific region upon a request of ITSU member states.

NWPTA collects seismic data from Japanese and global networks  and determines  hypocenter and magnitude and exchanges information with PTWC in Hawaii.
If tsunami will be expected, JMA will estimate arrival time and height of tsunami. JMA will provide tsunami information to relevant countries around the Northwest Pacific.

## Northwest Pacific Tsunami Advisory

***OBJECTIVE***
**●***** ******To offer useful information including ******  ***
***  ***_***tsunami amplitude forecasts***_
**●***** ******To cover the marginal seas adjacent to ***
***  ******Northwest Pacific***
*** ****** ***_*In conjunction with the tsunami bulletins from PTWC*_
* *
* *_*As an advisory for the actions taken by the recipient*_
* *_*countries such as alerting the people and announcing *_
* *_*evacuation notices on their own responsibility*_

## Slide 4

**Notes:**

When an earthquake greater than magnitude 6.5 occurs in the region indicated by shaded area, the NWPTAC initially determine the location and magnitude of the earthquake using global seismic data and evaluates potential of tsunami based on the source parameters. If tsunami expected, the NWPTAC also estimates the tsunami heights and the arrival times from pre-calculated tsunami database. Then, NWPTAC provide tsunami information to relevant countries in 20 to 30 minutes by means of GTS, E-mail and facsimile. If a tsunami would actually be observed, the NWPTAC would provide tsunami observations as subsequent information.

It is also expected that NWPTA will allow the recipient countries to make better judgment about the actions to be taken against the tsunami threat in conjunction with the tsunami bulletins from PTWC.  However, NWPTA should be regarded as an advisory for the actions taken by the recipient countries such as alerting the people and announcing evacuation notices on their own responsibility.

The coverage area of NWPTAC will be expanded to marginal seas in step-by-step basis.
In April 2006, NWPTAC extended the area to the South China Sea. 

##   Seismic Waveform Data Collection

**                                          ****for Northwest Pacific Tsunami Advisory**

- Worldwide Network (Broadband Stations)

- IRIS/USGS(accessing LISS servers) and IRIS/IDA(accessing IRIS server) seismic data via the Internet.

**Notes:**
This slide shows the seismic network for determination of source parameters. 
This network is IRIS/USGS and IRIS/IDA. We are collecting data through the Internet.

## Seismic waveforms from IRIS

**Notes:**
This slide is an example of  seismic waveforms obtained by IRIS network through the Internet. 
We measure P arrival times of some stations and calculate location of earthquake by least square method.

## Determination of Hypocenter

**Notes:**
This slide shows the location of the earthquake determined by our system .

## Database

**Database**

- Numerical Simulation

- Hypoceneter
- Magnitude

**Tsunami Amplitude**
**Arrival Time**

- Even a most-advanced computer needs much time to simulate tsunami propagation!

**Notes:**
日本の近地津波と同様にデータベースを用いて、津波の高さと到達時刻を予測します。

## Forecast Points in the South China Sea

**Notes:**
この黒丸が予測地点です。
南シナ海部分を拡大するとこのようになります。

## Means of dissemination

- Global Telecommunication System (GTS) of World Meteorological Organization (WMO)
-  WEPA40 RJTD
- E-mail
- Facsimile

**Notes:**
Three methods are available for reception of the tsunami information.
The first is GTS.
 The tsunami information is provided through the GTS in the framework of the international  communication system of WMO.
 The heading is WEPA40.
The second is E-mail and the third is facsimile.
If you wish that you receive the tsunami information by two kinds of methods, or two or more organizations in your country  receive the tsunami information,  our Center take account of your request. 

## Case Study 1- Pacific Wave ’06 source -

## Background seismicity 

- (M>=6.5,d<=100km) & distribution of disastrous earthquakes in the past

- Ref.  Utsu (personal comm.) for 801-2001
-          PDE for 2002-
-                 (M>=6.5, d<=100km)

## Simulation example – 1(M=8.5, depth=10km, reverse fault)

- Maximum wave amplitude

- Tsunami travel time

- (in hours)

- epicenter

## Pacific Wave ‘06 source

- Tsunami Travel Time

- Estimated Tsunami Amplitude

- Amplitude (m)

## Elapsed Time

_**Pacific Wave ’06 **_

- 5 M.

- Detection of
- Earthquake

- 10 M.

- Determination of HYP. & M

- EQ.

**NWPTA 001**

- ETA & AMP.

- 15 M.

- 20 M.

- 25 M.

- 30 M.

- 1 H.

- Tsunami Observation
-    *Ishigakijima*
-    *Naha*

**NWPTA 002**

- HYP & M

- Information from PTWC

**Notes:**
For example, let’s consider the case of occurrence of a earthquake near Philippines.
This source was used in the exercise Pacific wave 06
About 20 minute later, JMA issues earthquake information, and starts to monitor tidal data.
About 30 minutes later,  tsunami will arrive at Adak. JMA might receive information from the PTWC.
JMA evaluate the potential of tsunami to Japan and if affection of tsunami will be identified, Jma will issue tsunami warning about 2 hours before expected arrival time.

地震発生後、数分程度で地震波を検地、震源、Mの推定を行う
十数分後にPTWCから情報が送られてくる。
PTWC震源とConsistent with PTWC parameters
震源、Mに基づき、津波の到達時刻、高さ予測する、NWPTA第1号を発表する。
日本の検潮所で津波が観測し始める、観測値を掲載したNWPTA第2号が発表される。
その後は観測される験潮所が増加、あるいはより大きな津波が観測されたなどの情報があれば、続報が発表される。
特に変化が無い限り、続報は発表されない。解除の知らせもない。

## Northwest Pacific Tsunami Advisory

***    CONTENTS***
*  1  **Earthquake Information*
*  2  **Evaluation of Tsunamigenic Potential*
*  3  **Estimated Amplitude and Arrival Time of Tsunami*
*  **4**  **Tsunami Observation Data*
***         ***

## Example of Northwest Pacific Tsunami Advisory 

**Earthquake Information**

**Potential of Tsunami**

**Notes:**
This is an example of Northwest Pacific tsunami advisory. When the earthquake of M6.9 occurred on November 14 2005, this bulletin was actually issued. 
NWPTA contains earthquake information, evaluation of tsunamigenic potential and estimated tsunami height and arrival time at forecast points.
In this case, this bulletin shows that estimated tsunami heights don’t exceed 0.5m at any forecast points.
If tsunamis are observed at sea level stations, those observation will be also provided.  

## Example of Northwest Pacific Tsunami Advisory (continuation)

- Example of Northwest Pacific Tsunami Advisory (continuation)

**Estimated Tsunami Height**

**Notes:**
This is an example of Northwest Pacific tsunami advisory. When the earthquake of M6.9 occurred on November 14 2005, this bulletin was actually issued. 
NWPTA contains earthquake information, evaluation of tsunamigenic potential and estimated tsunami height and arrival time at forecast points.
In this case, this bulletin shows that estimated tsunami heights don’t exceed 0.5m at any forecast points.
If tsunamis are observed at sea level stations, those observation will be also provided.  

## Example of Northwest Pacific Tsunami Advisory (continuation)

- Example of Northwest Pacific Tsunami Advisory (continuation)

**Tsunami Observation**

**Notes:**
This is an example of Northwest Pacific tsunami advisory. When the earthquake of M6.9 occurred on November 14 2005, this bulletin was actually issued. 
NWPTA contains earthquake information, evaluation of tsunamigenic potential and estimated tsunami height and arrival time at forecast points.
In this case, this bulletin shows that estimated tsunami heights don’t exceed 0.5m at any forecast points.
If tsunamis are observed at sea level stations, those observation will be also provided.  

赤字に注意。