Deutsches Ozeanographisches
Datenzentrum Inventur der Sonne1-Reise SO227 (DOD-Ref-No.20130118)
Inventory of Sonne1 Cruise SO227 (DOD-Ref-No.20130118)

Plattform
Platform
Reise-Nr.
Cruise-No.
Zeitraum
Period
Projekt
Project
Arbeitsgebiet
Working area
Sonne1 SO227 30.03.2013 - 03.05.2013   North Pacific Ocean  

Fahrtleiter
Chief Scientist
Institut
Institute
Auslaufhafen
Port of departure
Einlaufhafen
Port of return
Stationskarte
Station map
Schiffsroute
Trackchart
Berndt Christian GEOMAR Helmholtz-Zentrum fur Ozeanforschung Kiel Kaohsiung Kang Kaohsiung Kang   

Ziel der Reise / Objectives of Cruise:

The underlying scientific motivation of SO227 was to constrain the geological processes that control the distribution and saturation of hydrate in marine sediments. The most important objective of the cruise was to observe the effect of additional fluid advection along blind thrusts into the gas hydrate stability zone. With its clear distinction into a passive margin and an active margin the area SW of Taiwan is particularly well suited for this kind of research because it is very well studied and it is known where the tectonic structures of the compression and subduction zone disturb the otherwise fairly homogeneous surface sediments of the margin. After a reconnaissance survey using multi beam echo sounder and side scan sonar we selected two sites that are typical for the active and passive margin, respectively. At these two sites we carried out comprehensive geophysical experiments including high-resolution 3D seismic imaging with the P-Cable system, ocean bottom seismometer (OBS) deployments, controlled source electromagnetic (CSEM) measurements, heat flow measurements, and ground-truthing using HyBis and TV grab. While the P-Cable data allow us to determine the internal structure of the study areas down to a depth of approximately 500 m below sea floor, the OBS and CSEM data will constrain the hydrate and free gas saturation along two-dimensional transect through the 3D seismic cubes. The heat flow data will provide information on the thermal conditions of the sediments. The first site covers the Formosa Ridge on the passive margin of the South China Sea. The ridge is the result of canyon erosion in the north, west, and east. The highresolution three-dimensional seismic data show a continuous bottom simulating reflector (BSR) marking the base of the hydrate stability zone. Particularly, underneath the canyon in the north the BSR is much shallower than underneath the centre of the ridge. This may indicates that the canyon incision has changed the hydrate stability field and that hydrate formation at depth has not been able to adjust to the new pressure and temperature conditions. The second site includes a roll over anticline called Four-Way-Closure Ridge which is the surface expression of an underlying blind thrust. In this area numerous high amplitude reflectors occur above the BSR. This unusual observation may suggest very high gas hydrate saturations and coeval presence of free gas and gas hydrate in the sediments. Evaluation of the OBS and CSEM data will allow to test this hypothesis. The 3D seismic data clearly show fluid migration pathways through the gas hydrate stability to the sea floor. Sea floor video footage and sampling confirmed the presence of on-going methane seepage at the Formosa Ridge above the fluid migration pathway imaged in the 3D seismic data. They also establish that there is at least one seep on the Four-Way-Closure Ridge at which methane is released into the ocean above another seismically imaged fluid migration pathway. This is the first active seep site with chemosynthetic ecosystems discovered on the active margin SW off Taiwan.

Messungen / Measurements

Institut
Institute
Wissenschaftler
Scientist
Anzahl
Number
Einheit
Unit
Typ der Messungen
Type of measurements
Kommentar
Comments
Daten im DOD
Data in DOD
GEOMAH Berndt Christian 7 stations G02
Grab
. 29.04.2013 no
GEOMAH Berndt Christian 10 diving(s) G08
Bottom photography
. 26.04.2013 no
GEOMAH Klaucke Ingo 11 profiles G24
Long/short range side scan sonar
. 02.04.2013 no
GEOMAH Berndt Christian 97 profiles G26
Seismic refraction (no.of nautical miles)
. 05.04.2013 no
GEOMAH Jegen-Kulcsar Marion 2 profiles G28
Magnetic measurements
. 13.04.2013 no
GEOMAH Berndt Christian 140 profiles G74
Multi-beam echosounding
. 02.04.2013 no
GEOMAH Berndt Christian 81 profiles G76
Multichannel seismic reflection
. 05.04.2013 no
GEOMAH Berndt Christian 2 stations H10
CTD-Stations
. 02.04.2013 no
GEOMAH Feseker Tomas 45 stations H72
Thermistor chain
. 11.04.2013 no
GEOMAH Berndt Christian 1 n miles H80
Other physical measurements
Underway measurements during the whole trip such as coordinates, depth, meteorological parameter and so on yes

Verankerungen / Moorings

Institut
Institute
Wissenschaftler
Scientist
Typ der Messungen
Type of measurements
Kommentar
Comments
geogr.Breite
Latitude
geogr.Länge
Longitude
Daten im DOD
Data in DOD
GEOMAH Berndt Christian G02 - 22° 3.0' N 119° 48.0' E no
GEOMAH Berndt Christian G02 - 22° 7.0' N 119° 17.0' E no
GEOMAH Berndt Christian G08 - 22° 4.0' N 119° 48.0' E no
GEOMAH Klaucke Ingo G24 - 22° 4.0' N 119° 16.0' E no
GEOMAH Klaucke Ingo G24 - 22° 4.0' N 119° 47.0' E no
GEOMAH Berndt Christian G26 - 22° 6.0' N 119° 45.0' E no
GEOMAH Berndt Christian G26 - 22° 12.0' N 119° 20.0' E no
GEOMAH Jegen-Kulcsar Marion G28 - 22° 3.0' N 119° 48.0' E no
GEOMAH Jegen-Kulcsar Marion G28 - 22° 5.0' N 119° 19.0' E no
GEOMAH Berndt Christian G74 - 22° 4.0' N 119° 23.0' E no
GEOMAH Berndt Christian G74 - 22° 5.0' N 119° 47.0' E no
GEOMAH Berndt Christian G76 - 22° 3.0' N 119° 49.0' E no
GEOMAH Berndt Christian G76 - 22° 6.0' N 119° 17.0' E no
GEOMAH Berndt Christian H10 - 21° 57.0' N 119° 31.0' E no
GEOMAH Berndt Christian H10 - 22° 0.0' N 119° 40.0' E no
GEOMAH Feseker Tomas H72 - 22° 4.0' N 119° 5.0' E no
GEOMAH Feseker Tomas H72 - 22° 6.0' N 119° 15.0' E no
16.11.2019