Skip to main content

2013 05 - R/V Sonne Cruise SO228 - EIS­PAC / WEST­WIND / SI­ODP

Kaoh­si­ung (TWN)- Towns­vil­le (AUS)

04.05.2013 - 23.06.2013

Chief Seismic: Dr. Tilmann Schwenk

MTU Participants: Bergmann, Gernhardt, Wenau



The RV SON­NE Ex­pe­di­ti­on SO-228 com­bi­ned three re­se­arch pro­po­sals for the Wes­tern Pa­ci­fic

1. Glacial sequestration of atmospheric CO2 in the deep Pacific (EISPAC)

Com­pa­red to in­ter­gla­ci­al pe­ri­ods, the at­mo­s­phe­ric CO2 con­tent was si­gni­fi­cant­ly re­du­ced
du­ring gla­ci­al pe­ri­ods, which has been re­la­ted to a tem­po­ral se­que­stra­ti­on of CO2 in the deep oce­an. To date, no cle­ar evi­dence exists for a pos­tu­la­ted gla­ci­al abys­sal re­ser­voir of the at­mo­s­phe­ric CO2 in the Pa­ci­fic and its de­gla­ci­al re­lease through the Sou­thern Oce­an. We aim to ve­ri­fy the hy­po­the­sis of the gla­ci­al se­que­stra­ti­on of at­mo­s­phe­ric CO2 in the deep Pa­ci­fic. We sam­p­led se­di­ments and the wa­ter co­lumn on the con­ti­nen­tal mar­gin off Mind­a­nao (Phil­ip­pi­nes) and Pa­pua New Gui­nea. The sam­ples/data will al­low us to test whe­ther and how at­mo­s­phe­ric CO2 was se­ques­te­red into abys­sal Pa­ci­fic du­ring gla­ci­als for thousands of ye­ars and then ven­ti­la­ted ra­pidly through in­ter­me­dia­te wa­ters that cir­cu­la­ted through the Sou­thern Oce­an du­ring gla­ci­al ter­mi­na­ti­ons.

2. Hydroclimate of the Western Pacific Warm Pool (WPWP) and its influence on the Indonesian Throughflow (WESTWIND)

The hy­dro­lo­gi­cal cy­cle of the Wes­tern Pa­ci­fic Warm Pool (WPWP) is pre­sent­ly in­flu­en­ced by
va­ria­ti­ons in El Niño-Sou­thern Oscil­la­ti­on (ENSO) as well as by high la­ti­tu­de cli­ma­te. De­s­pi­te
the si­gni­fi­can­ce of this cy­cle for the re­gio­nal cli­ma­te and its ac­tive role in glo­bal cir­cu­la­ti­on, its
long-term va­ria­ti­on and its in­flu­ence on the In­do­ne­si­an Through­flow (ITF) are lar­ge­ly un­k­nown. Ai­ming to bet­ter un­der­stand the pro­ces­ses in or­der to im­pro­ve the si­mu­la­ti­on of the dy­na­mics of the WPWP in the mo­dels, we co­red ra­pidly ac­cu­mu­la­ting se­di­ments off Phil­ip­pi­nes and Pa­pua New Gui­nea, a cri­ti­cal re­gi­on for un­der­stan­ding the re­s­pon­se of the tro­pi­cal hy­dro­lo­gi­cal cy­cle to dif­fe­rent for­cings, but whe­re very few high-qua­li­ty pa­leo­cli­ma­te re­con­struc­tions are avail­able. The­se re­cor­ds will enable the re­con­struc­tion of zo­nal and me­r­idio­nal gra­di­ents in tem­pe­ra­tu­re, sal­in­i­ty, and pre­ci­pi­ta­ti­on, and iso­la­te the re­la­ti­ve in­flu­ence of dif­fe­rent po­ten­ti­al for­cing me­cha­nisms un­der dif­fe­rent boun­da­ry con­di­ti­ons. Re­sults of this re­se­arch pro­ject will ad­van­ce know­ledge on the cli­ma­te sen­si­ti­vi­ty of the WPWP.

3. Seismic Survey to support the IODP-full proposal 799 (SIODP)

We con­duc­ted seis­mic sur­vey (mul­ti-chan­nel seis­mic, MSC) at two sites in the Da­vao Bay and south of Ma­nus Is­land that had been pro­po­sed as drill sites in the IODP-full pro­po­sal 799 (Pa­leo­cea­no­gra­phic re­cor­ds of the Wes­tern Pa­ci­fic Warm Pool va­ria­bi­li­ty by Ro­sen­thal, Moun­tain, Moh­ta­di et al.). The ex­pe­di­ti­on took place in 2016 (IODP ex­pe­di­ti­on #363) and whi­le the Da­vao Bay site was aban­do­ned due to safe­ty con­cerns, the site south of Ma­nus Is­land could be suc­cess­ful­ly dril­led (see

Chief Scientist:


PD Dr. Ma­hyar Moh­ta­di


+49 421 21865660


+49 421 21865653



Sampling sites east off Mindanao (Philippines)


Sampling sites off Papua New Guinea


Bathymetry map of the Davao Bay


Multi-corer deployment off Mindanao


Filtered seawater for rare earth element analysis


Nach oben