Anat (21)

Aviel Ron (54)

Ofer (17)

In Memory of Aviel Ron

Director General of the Survey of Israel (1994-2002)

and his two children-Anat and Ofer

Murdered during a terror attack in Haifa 31.03.2002

Israeli Coast Sea Level Changes During 1958-2001

Boris Shirman boris@soi.gov.il

Yossi Melzer melzer@soi.gov.il

Survey of Israel

Targets of Sea Level Monitoring in SOI

Update the “zero level” value of the geodetic vertical network

Determination of long term changes and variation in sea level

Maritime Mapping

Collecting Data for interdisciplinary research

The Mediterranean Basin

and the Israeli Coast

SOI Tide gauge array along the Med. Sea 2002

(Satellite Image)

SOI Tide gauge array along the Med. Sea 2002

Port Of Haifa

Tel Aviv Marina

Port of Ashdod

Ashqelon Marina

Port of HaifaCooperation between SOI and IPA

Radarsensor Kalesto

Port Of HaifaCooperation between SOI and IPA

Tel Aviv – Marina

SOI station-digital float tide gauge

Port of Ashdod

Cooperation between SOI and IPA-digital float tide

gauge

Ashkelon Marina

SOI station-digital float tide gauge

Tide Gauge

Calibration

Maintenance Procedure

Data Download – Every week

Tide Gauge Calibration – Every week

Data Processing – Every week

Tide Gauge and BM stability – Twice a year

Pipe maintenance by diver – Twice a year

Annual Report

Equipment maintenance-according needs

Types of data used for the study

Years Location data source data sampling data source

1958-1960 Ashdod Tables Month Avr. IPA 1961-1984 Ashdod Tables Hour Avr. IPA 1962-1989 Yafo Analog Digitizing SOI

1990-1995 Ashdod Analog Digitizing SOI

1996-2001 Tel-Aviv Digital 5 min SOI

Tel-A viv

Ashdod

Ashdod - Tel-Aviv

m ean = 1 .0 cmst. dev. = 1 .1 cm

260 270 280 290 300 310Ju lian days (16 S ep-13 N ov), 1999

-0 .2

0.0

0.2

0.4

Tid

e, m

-0 .2

0.0

0.2

0.4

Tid

e, m

-0 .2

0.0

0.2

Diff

ere

nce

s, m

è åúù øé

à ëñ ì å

è å ç ù åï

à ç ù åï Comparison

Between

Tel Aviv

data

and…

Ashdod

data

Mean: 1 cm

f req ue ncy , 1 /da y

0

10000

20000

30000

Spe

ctra

l am

plitu

de, c

m

1 .0 2.0 3.0 4.0

01 03 04 06 08 10 12m on th

-40

-20

0

20

40

60

80

Sea

leve

l, cm

S ea levelT el-Aviv 2000

diurnal

sem idiurnal

monthly

Spectrum Analysis

Recorded

f req ue nc y, 1 /da y

0

10000

20000

30000

Spe

ctra

l am

plitu

de, c

m

1 .0 2.0 3.0 4.0

01 03 04 06 08 10 12m on th

-40

-20

0

20

40

60S

ea le

vel,

cmA stronom ica l tide 2000

diurnal

sem id iurnal

month ly

Spectrum Analysis

Predicted

62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86Years

-30

-20

-10

0

10

20

30S

ea le

vel,

cm

-30

-20

-10

0

10

20

30

Sea

lev

diffe

renc

es, c

m

Dif ferenc es be twe en As hd od an d Y afo s tations

Co m pile d A sh do d a nd Ya fo rec ord s reffe re d to Y afo da tum

Comparison between the monthly mean sea level of Yafo and Ashdod

The differences corrected to Yafo Datum (remained stable)

S.D. of 4 cm (random according to stat. test)

62-67 :-0.2cm

68-83 :-4.8cm

f req ue nc y, 1 /ye ar

0

500

1000

1500

Spe

ctra

l am

plitu

de, c

m

1958 1961 1964 1967 1970 1973 1976 1979 1982 1985 1988 1991 1994 1997 2000Ye ar

-40

-30

-20

-10

0

10

20

30

40

Sea

leve

l, cm

S pe ctrum

E as t M editer ran ea n S ea lev el cha ng es

1.0 2.0 3.0 4.0 5.0 6.0

Israeli Cost Sea Level 1958-2001

Spectrum Analysis

FFT

Yearly cycle

Third year cycle

)Meteo. Effect(

Half year cycle

Multi year cycle~20y

Average: +5.9 cm

58 61 64 67 70 73 76 79 82 85 88 91 94 97 00Years

-8

-4

0

4

8

12

16

Sea

leve

l, cm

On e y ea r a verag ed & eig ht yea rs sm oo the dEa st Me dite rra ne an Se a le ve l (19 58 -20 01 )

Israeli Coast Yearly mean sea level 1958-2001

67 69 71 73 75 77 79 81 83 85 87 89 91 93Years

(m idd le of averag ing period)

0

2

4

6

8

1018

.6 y

ears

ave

rage

d se

a le

vel,

cmTime serious avereges during a period of 18.6 years

Future Plans

To improve accuracy of the digitized data

To digitize analog data previous to 1958

To apply advanced models

Summary

The research indicates the existence of several periods of sea level cycles: Monthly, Yearly, Multi-Yearly

Since 1991 the sea level rose more than 10 cm

We must follow the present multi year cycle in order to verify sea level rise along the Israeli coast

We are looking to find correlation with other sites at the Mediterranean Sea