1

Preparatory Work on Renewing the

Canadian National Seismograph Network

Tim Côté and Wayne Edwards Canadian Hazards Information Service,

Geological Survey of Canada

Natural Resources Canada

September 28, 2015

2

Questions Addressed

What does NRCan/GSC/CHIS do? Background

What is wrong with the current network? Review of CNSN network

What stations are good or bad? Study existing network

What equipment is available? Market survey of seismic equipment

What are other agencies doing? Review of other networks

What do we need? Define technical specifications

How do we buy it? Procurement tools and techniques

3

Who We Are. What We Do.

Natural Resources Canada (NRCan)

Geological Survey of Canada (GSC)

Canadian Hazards Information Service (CHIS)

Meet Emergency Management Obligations

CHIS Activities Earthquake Monitoring, Nuclear Explosion Monitoring

Tsunamis, Landslides, Volcanic Eruptions

Emergency Mapping, Nuclear Emergency Response

Geomagnetic Monitoring, Space Weather Forecasting

4

Earthquake Monitoring Activities

Mandate from: Emergency Management Act

“the provision of information on the actual or

probable occurrence and intensity of

earthquakes”.

Seismic Monitoring

Collaboration with other agencies – data

exchange

Rapid Response for Earthquake Info

Providing Public Information

Earthquake Hazard Assessment

5

Nuclear Explosion Monitoring Activities

Mandate from: Comprehensive Nuclear

Test Ban Treaty Implementation Act

Operate IMS stations

Operate an Independent SubNetwork, ISN

Collect and forward IMS data to the

CTBTO International Data Centre in

Vienna

Provide nuclear monitoring support for

Government of Canada

6

Monitoring Network

Operate 11 stations as part of the International

Monitoring System: 3 primary and 6 auxiliary

seismic, 1 infrasoud, and 1 hydroacoustic

Operate the Canadian National Seismic

Network (CNSN)

~ 150 weak motion seismographs

~ 120 strong motion accelerographs

Operate other temporary seismograph

stations and/or networks

On behalf of other Canadian research groups

7

Weak Motion Seismograph Station Map

8

Two Data Centres: Ottawa, Sidney

Parallel/Independent Operation

Redundant Systems

Redundant Communication Links

9

Types of Equipment In Use 2 main types of weak-motion equipment used

Vertical-only Short Period sampled at 100 s/s

In-house designed short period digitizer (SPD)

S13 Seismometer

3 Component Broadband sampled at 40 or

100 s/s

In-house designed broadband geophysical

digitizer (GD/GD2)

Guralp CMG 3ESP & 3T seismos; STS1 seismo

Yellowknife array uses Guralp digitizers

and BB seismos after recent upgrade

Recently using Nanometrics digitizers,

Trillium seismos, Titan accelerometers, and

Libra satellite systems (from temporary networks)

10

End Of Life

Most equipment is ~20 years old

Can no longer repair digitizers (lack of parts)

Many vaults in poor condition

Acquisition software tied to in-house digitizer

Most of the network is reaching End-Of-Life

Time to renew the entire network

Funding secured to: upgrade ~150 broadband 3 channel weak motion stations

Install strong motion at ~2/3 weak motion stations

11

How Do We Upgrade the Network?

What Stations Do We Upgrade?

Study the Stations in the Network How do the stations compare?

Is one better than another?

What could be modified that would improve station

performance?

Reduce noise, improve communications, harden power

Is a station redundant?

Is the station even worthwhile renewing?

Can the station perform better somewhere else?

12

Need A Quantitative Measure of

Usefulness & Performance

Overall performance of a seismic station is a

combination of several factors:

Data Quality – Station noise. What shakes around the station

other than earthquakes?

Data Availability – How often is data received from the station?

Data Usage – How does the station contribute to the network?

Usefulness in monitoring, locating earthquakes in region

Network Coverage – Where are there holes in the network?

What happens if we remove a station?

Station maintenance

Ease of physical access, station complexity, general robustness

Operating costs – How much $$$ it take to run and maintain the

station?

13

Data Quality:

Noise Levels at CNSN stations

Compare noise levels at all CNSN stations with: Peterson high and low models of global seismic noise (NHNM/NLNM).

Other CNSN stations

Using 6+ months of continuous data, the noise

characteristics of the CNSN are analysed, with median

and upper/lower percentiles compared to the NHNM and

NLNM.

Stations can be ranked in terms of performance in the

network in terms of noise in the monitoring band. A, B, C, D Lower 25%, Lower Middle 25%, Upper Middle 25%,

Upper 25%

14

The Current CNSN Network Noise

10-3

10-2

10-1

100

101

102

-220

-200

-180

-160

-140

-120

-100

-80

-60

Po

we

r d

B (

rel. 1

(m

/s)2

/Hz)

Frequency (Hz)

CNSN Network Median Spectrum: 118 stations

NHNM/NLNM

Median (50%)

5%

10%

25%

75%

90%

95%

Microseism Band (coupled ocean wave interactions)

0.05 – 1 Hz

Regional Earthquake Monitoring Band ~0.5 Hz – 10 Hz

Normal Modes of the Earth < ~5 mHz

Teleseimic Monitoring Band

~0.5 – 3 Hz

Typical CNSN Station:

Bedrock

Surface/Cave

Multiple lower frequency cutoffs 0.5 sec

1 sec

30 sec

60 sec

100 sec

120 sec

360 sec

Upper Nyquist frequencies 10 Hz

20 Hz

50 Hz

A

D

15

Data Availability: The availability of data

from any station is a prime

measure of the quality of a

station.

Without available station

data no earthquake

monitoring is possible

Data availability is a

measure of overall station

robustness:

Communications

Infrastructure

Instruments

Stations can be ranked by

data availability

0 50 100 150 2000

10

20

30

40

50

60

70

80

90

100

CNSN Station #

Da

ta A

va

ilab

ility

(%

)

2014 Data (178 CNSN stations)

Distribution 5th – 25.3% 10th – 25.5% 25th – 73.9% 50th – 97.0%

75th – 99.89% 95th – 99.97%

D

C

B

A

16

Data Usage:

General Station Usefulness

Using the National Earthquake Database (NEDB), a

count is made of the number of times a station is used in

an earthquake location

Stations are classified into one of three areas: Northern Canada (Latitude >60°N)

Western Canada (Longitude >100°W)

Eastern Canada (Longitude <100°W)

Stations are then ordered according to usage and

assigned a class: A,B, C, or D. A: Upper 25th% of all stations

B: Upper Middle 25th%

B: Lower Middle 25th%

B: Lowest 25th%

17

0

10

20

30

40

50

60

70

80SI

LOM

ALO

SUN

OEF

OK

ILO

PN

PO

SJN

NO

RIO

TBO

QC

QK

GN

OM

OQ

OTT

A1

1H

AL

KA

PO

VIM

OA

TKO

GTO

MN

TQSA

DO

A1

6M

NQ

A5

4G

RQ

DR

LNEP

LOV

AB

QC

HEG

VLD

QSO

LOP

KLO

EEO

ULM

WB

OLG

4Q

CR

LOLM

QG

BN

A6

4SC

HQ

NA

TG A6

1FC

CD

PQ

DA

QG

AC

LMN

TRQ

A2

1SM

QG

GN

CN

QG

SQ ICQ

BA

TG

Nu

mb

er o

f T

imes

Use

d in

an

Ear

thq

uak

e Lo

cati

on

CNSN Station

Eastern Canada (June 2013 - June 2014)

D

C

B

A

18

0

200

400

600

800

1000

1200

1400

LIB

CLR

S

EDM

HO

PB

WA

LA

BC

BC

BFS

B

VG

Z

BLB

C

HN

BB

WSL

R

PN

T

MA

SB

SLEB

SNB

GO

BB

LZB

MN

B

VD

B

PG

C

BIB

BN

AB

WP

B

VIB

FNB

B

BM

BC

LLLB

YOU

B

NLL

B

ETB

HG

1B

HG

4B

PLB

C

PFB FS

B

ND

B

GD

R

UB

RB

TXB

SHB

OZB

MO

BC

NC

RB

DLB

C

RU

BB

HG

3B

MG

B

WO

SB

BN

B

CB

B

DIB

BTB

EDB

BP

BC

HO

LB

MA

YB

PH

C

BB

B

Nu

mb

er

of

Tim

es

Use

d in

a E

arth

qu

ake

Loca

tio

n

CNSN Station

Western Canada (June 2013- June 2014)

A

D

C

B

19

Network Coverage:

CNSN Network Threshold Map

20

Network Coverage: What Happens

If We Remove A Station? How does this affect magnitude completeness?

Measure of station density/sparseness in a region

Rank stations based on (area * delta magnitude)

Remove station CBB, Campbell River Remove station RES, Resolute

21

Table of Evaluation

Using all the various rankings an overview table will be constructed

to establish a general ranking based on ALL categories

In this scenario:

Station A is a MUST keep and 1st to be addressed.

Station D is a MUST consider as a low priority and a possible MOVE or CLOSE.

This table will provide an objective and quantitative measure and

ranking of the overall importance of stations in the renewed CNSN.

Name Data Availability

Data Quality

Data Usage

Network Coverage

Station Maintenance

Operating Costs

Overall Rank

Station A 100% A A B Moderate $$ 1

Station B 95% C B A Easy $ 2

Station C 82% B C C Moderate $$ 3

Station D 20% B D D Hard $$$ 4

22

How Do We Upgrade the Network?

What equipment is available?

Market survey of seismic equipment

Majority of work completed in fall 2014

Researched 9 companies

eentec, Earth Data Division, gempa, GeoSig, Geotech, Guralp,

Kinemetrics, Nanometrics and Trimble

Focused on products appropriate for NRCan

seismometers, accelerometers, digitizers, all-in-one devices

Discussions with management, technical and sales staff

face-to-face meetings (San Francisco, Dec 2014), phone, email, via

web

23

Equipment Surveyed seismometers, digitizers, accelerometers

24

Market Survey Outputs

Report on Technology Options

Including recommendations

3 tables / spreadsheets comparing:

seismometers

digitizers

accelerometers

Market Survey Summary for colleagues

25

How Do We Upgrade the Network?

What are other Agencies doing?

Review of other networks Tasked to review equipment, software, processes and procedures of

other large and small seismic networks

Conducted over past several years

Visited or met with several network & data centre operators

ANSS (USGS), TA (US Array), PNSN (Washington), AEIC (Alaska), ETHZ

(Switzerland), INGV (Italy), GeoNet (NZ), GA (Australia), CTBTO IMS

(Vienna), ORFEUS (Europe), …

Discussions with field technicians, analysts & researchers, data centre

staff, managers

face-to-face visits, discussions around meetings, phone, email

Learned many Best-Practices

Learned about manufacturers reputations

26

Good News and Bad News

Lots of good and bad products available

Need to be careful with RFP specifications

Lots of good and not-so-good companies

Reputation matters, so factor into RFP specifications

Lots of options available, maybe too many

Need to be precise with RFP specifications, keep focus

Lots of interoperability between products, but not

standardized and or completely supported

May need to define interfaces in RFP specifications

Lots of decisions to make, but can learn from others

Will take time to justify all RFP specifications

27

Results and Findings

Our network requirements are in the “sweet spot”

between expensive, high-end research equipment

and low cost, lower quality, commodity equipment

State Of Health and QC data and/or reports is basic

Most equipment can support some type of

Earthquake Early Warning or low latency applications

Separate sensor and digitizer more flexible and

standard than all-in-one solutions

Standardize on 6 channel digitizers instead of

separate weak and strong motion digitizers to

simplify data handling

28

Surface Vault versus Post Hole

Proper vault construction is important

Surface vaults need very good

insulation to reduce thermal variations

which leads to long period noise, etc

Postholes are a good alternative

GAC test - comparison of different

surface vaults with posthole vault

Post hole depth of ~ 2-3 metres can

reduce noise significantly

29

AEIC Tank, T240 before

5M post hole, T120PH after

Harding Lake, Alaska (HDA) (courtesy Natalie Rupert)

30

HDA Performance, Surface - top, PostHole – bottom (courtesy Natalie Rupert)

31

(courtesy Frank Vernon)

32

General Challenges

Do we have enough money to fix (or move) many

of the problematic stations?

Adding strong motion and GNSS/GPS data

Data acquisition software issues

Tight binding of digitizers and acquisition sw

May not work with existing data centre processing software

Need new monitoring, reporting, tracking & QC sw

How to handle CTBTO IMS stations – separately?

Telecommunication issues – Currently not enough

bandwidth

33

Telecommunication Challenges

Bandwidth Calculations Digitizer type CNSN

Number of channels 3

Sample rate, sps 40

Packet duration, seconds 6

Compression bytes/pkt 1.2

Packet overhead, bytes 20

UDP overhead, bytes 8

IP overhead, bytes 20

Ethernet overhead, bytes 18

retransmission ratio 1.1

packet size, bytes 354

bits/s/channel 519

bits/s for 1 data centre 1558

bits/s for 2 data centre 3115

CNSN

3

40

6

1.5

20

8

20

18

1.1

426

625

1874

3749

CNSN

3

100

6

1.5

20

8

20

18

1.1

966

1417

4250

8501

CNSN

6

100

6

1.5

20

8

20

18

1.1

966

1417

8501

17002

~q330

6

100

1

1.5

40

8

20

18

1.1

236

2077

12461

24922

Increases in • number of data centres • bytes per sample • sample rate 40 -> 100 sps • number of channels • overhead of protocol

34

Trade-offs and Balances

Many channels & high sample rates

versus low communications bandwidth

Inefficient standard-based protocols versus well-

supported proprietary protocols

Low-noise sensors & good ($$$) vaults versus

simple, inexpensive surface vaults with moderate

sensors

Surface vault versus posthole

Low power requirements allow quiet remote

locations versus AC-power sites with good access

& communications and higher site noise

35

What We Need?

Define technical specifications

In determining requirements, consider input from

all sources: seismic network goals, CHIS

mandate, market survey report, analysis and

monitoring needs, research needs, field tech

concerns, management requirements, O&M costs

Determine and justify all requirements & options

E.g. How quiet do we need sites for monitoring?

for research?

30s, 60s, 120s or more, how broadband is broadband?

36

What We Need?

Define technical specifications Rate requirements as mandatory or preferable

Find a way to rate preferable features

Time consuming to define all specifications

Use USGS ANSS RFP specifications as base

Define minimum specifications for:

seismometers

accelerometers

digitizer

data centre acquisition software

37

How Do We Buy It?

Procurement Tools and Techniques

How many contracts for equipment? One or many?

One for simplicity. No need to define interfaces.

We can’t test/evaluate everything

Use external test results, e.g. USGS ANSS RFP test results

Find a way to rate reputation

Don’t evaluate/rate only on cost

1/3rd cost, 1/3rd preferable features, 1/3rd reputation

Request manufacturer quotations for all optional

hardware, software and services

This could save time

38

How Do We Buy It?

Procurement Tools and Techniques

Start by issuing “Request For Information (RFI)”.

Tell vendors what we think we want/need.

Ask “Could you meet our requirements?”

Ask vendors specific questions about their products e.g. How does your system collect, transmit and display State-of-Health data?

Ask about other options available

Based on results of RFI, prepare a “Request For

Proposal (RFP)”

Fine tune technical specifications and requirements

Issue RFP

Cross fingers

39

Conclusion

Network renewal is a complicated process

There are many, many issues involved

It will take time

To do a high quality job, NRCan needs to:

Determine limitations of current network & stations

Be aware of the current state of the seismological

equipment marketplace.

Follow best practices of other networks

Carefully define requirements/specifications

Assess bids in a way that will result in robust network