In Memory of Aviel Ron Director General of

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 Ofer (17) Aviel Ron (54) Anat (21)

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 Haifa Cooperation between SOI and IPA Radarsensor Kalesto

Port Of Haifa Cooperation between SOI and IPA

Tel Aviv – Marina SOI station-digital float tide gauge

Port of Ashdod Cooperation between SOI and IPA-digital float tide

Ashkelon Marina SOI station-digital float tide

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

ears Types of data used for the study Location data source data sampling data source Ashdod Tables Yafo Analog Ashdod Analog Month Avr. Hour Avr. Digitizing IPA SOI Tel-Aviv Digital 5 min SOI

Comparison Between Tel Aviv data and … Ashdod data Mean: 1 cm

Recorded Spectrum Analysis

Predicted Spectrum Analysis

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. 2 cm 68 -83: -4. 8 cm )

Israeli Cost Sea Level 1958 -2001 Average: +5. 9 cm Multi year cycle~20 y Yearly cycle Spectrum Analysis FFT Half year cycle Third year cycle (Meteo. Effect)

Israeli Coast Yearly mean sea level 1958 -2001

Time 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