antelope usage at hong kong observatory

Antelope Usage at Hong Kong Observatory

WOO Wang-chun

Global Seismographic Network

Hong Kong Po Shan (HKPS)a GSN affiliate station

Po Shan Seismograph Station (HKPS)

Operational since 18 Feb 2010

HKPS (Side View)

HKPS (Top View)

As-built Plan of the Seismic Chamber

As-built Plan of the Plinths

Master Network Diagram

Geodetic Survey

dbnoise of HKPS

HKPS on IRIS DMC

Geophysical Services of Hong Kong Observatory

Earthquake Monitoring Global Earthquake Information Services Near Events (within 200km of Hong

Kong) Locally Felt Earth Tremors

Tsunami Watch South China Sea Pacific Global

Products Earthquakes

Quick Earthquake Messages Strong Earthquake Reports Locally Felt Earth Tremor Reports

Tsunamis Tsunami Warning Tsunami Information Bulletin Special Press Releases

Media briefing and interviews Educational web pages, leaflets, talks

Quick Earthquake Messages

Quick Earthquake Messages

Criteria M6.0+ worldwide

Dissemination On Twitter By emails / SMS to special users

(media, news agencies, government bureaux/departments)

On Weibo (later this month) In Chinese (Traditional) and English Normally issued by computer

automatically On average posted in 12 minutes after

origin

Strong Earthquake Reports

Strong Earthquake Reports

Criteria M6.0+ worldwide (same as Quick Earthquake

Messages) Dissemination

By Fax to Government’s Information Services Department and Radio Station

In Chinese (Traditional) and English Issued manually Normally issued later than Quick

Earthquake Messages, but still within 20 minutes after origin

Locally Felt Earth Tremor Reports

HKO’s Seismic Analyses Constraints

No 7/24 seismologist on duty Automation is the only way to go

HKO’s Parameters Results from Antelope, if automatically

verified against those from PTWC, NEIC or WCATWC

Differences in latitude and longitude <= 1.0 Difference in magnitude <= 0.5

Parameters from other sources if and when necessary

Automatic Seismic Information Webpage (for

duty officers)

Hong Kong Seismograph Network

Automatic Analysis for Near Events

(for duty officers)

Experimental Quick Earthquake Intensity (for

duty officers)

Experimental Quick Earthquake Intensity (for

duty officers)

Seismic data processing

systemHKPS, HKC and local 8 stationsIRIS Data Management Centre UC San Diego (UCSD)GEOFON (Mediterranean, NE Atlantic and Indian Ocean )

Global Seismographic Network (GSN)

M >= 6.0 Lat & lon <= 1 deg

XML MINDS

Strong Earthquake Report /QEM (Magnitude 6.0+ )Pacific Tsunami Warning Centre (PTWC)

National Earthquake Information Centre (NEIC)

West Coast and Alaska Tsunami Warning Center (WCATWC).

GEOFON ( planned to add )

EPICS

Automatic Seismic Information

HKO Seismic data processing system

HKO website, ISD, RTHK

Quick Earthquake Message QEM

1. Locally Felt Earth Tremor Report

2. Updated Earthquake Report with Intensity and Epicentre location map

Locally Felt Earth Tremor

OCGIO email to SMS services

Message Dissemination

system

XML

QEMQEMHKO Twitter & Weibo(In progress)

QEM

廣東省地震局 (EAGP)

中國地震局 (CEA)

NEIC if any

Locally felt earth tremor

HKO Twitter and Weibo (In progress)

HKO Seismic data processing system

QEM

MINDS

1. Locally Felt Earth Tremor Report

2. Earthquake Report with Intensity and Epicentre location map

Message Dissemination

system

XML

QEM

HKO website, ISD, RTHK

Experimental Quick Earthquake Intensity

Problem: Magnitude sometimes not

be calculated so quickly even other earthquake parameters such as location can be spotted by our system.

a large earthquake followed by frequent aftershocks

two or more earthquakes occur within short period of time

Solution: The magnitude and other

parameters were adopted from other centres such as PTWC, USGS

System upgrade (Long term)

(A) Total Number of Earthquake Reports (M>=6.0) issued from 31 May 2011 to 31 July 2011 is 36Earthquake Parameters (Magnitude, Location etc) adopted from:

HKO seismic data processing

system

Other centres (PTWC, USGS

etc)295 (75%) 95 (25%)

(B) Total Number of Earthquake (M>=5.0) analyzed by our system from 31 May 2011 to 31 July 2011 is 390

~ 10 times events more than Earthquake report issued.

Earthquake Parameters (Magnitude, Location etc) adopted from:

HKO seismic data processing

system

Other centres (PTWC, USGS

etc)21 (58%) 15 (42%)

Problems Slow magnitude computation when

there are multiple events IRIS DMC sometimes has extensive

data outage for days, already added UCSD and GEOFON as sources

dbarchive and dbnoise no longer works

Cannot compute focal mechanism for most events