Processed seismic data of Cruise SO161 SPOC 2001

Within the frame of the comprehensive SPOC project (Subduction Processes off Chile) the SONNE cruises SO161 Leg 2 and 3 have been conducted between October 16th and November 29th, 2001, off central Chile between 28° and 44° S. In that period some 5,300 km were surveyed with multichannel seismic (MCS) reflection, magnetic, gravity, high-resolution bathymetric and echographic methods. In addition, approximately 3,900 km were surveyed with the same spectrum of methods but without MCS. The total number of 2D profiles was 48. Target was the variation of the subduction properties between the convergent oceanic Nazca and continental Southamerica plates and the different conditions that might influence the subduction process as there are: (1) age of the oceanic crust, (2) its structure and composition, (3) its sedimentary cover, (4) its thermal state, (5) the subduction angle and obliquity, and (6) the terrigenous sediment afflux from the continent. Furthermore, special focus was given to the subduction front, the subduction interface, the structure of the slope as well as to the forearc basin structure and history, and the general distribution of gas hydrate indicating bottom simulating reflectors (BSR's). The results are to be compared with previous studies of the Chilean active margin, e.g. CONDOR (SO 101 and 103) and CINCA (SO 104). The SPOC target area was subdivided into three sub-areas A,B and C. One area was chosen for a detailed survey by aid of a narrowly spaced grid and for a close link with a lot of partners. This area is characterized by a distinctly different margin type south of it is assumed. Moreover, the subducting portion of the aseismic Juan Fernandez Ridge is located in that area representing another important target of the survey. Advantageous conditions enabled the survey of an east-west profile south of Chiloé Island, providing a section through the submerged coastal Cordillera into the flooded longitudinal valley. Some results of Leg 2 and 3 are: In all areas A, B and C no subduction bulge (outer high) in the oceanic crust was visible perhaps due to the shortness of the profiles. The sedimentary cover of the oceanic crust is exceptionally thin, and the crustal thickness is generally quite "normal" with around 7 km derived from relatively weak Moho reflections. In area B a so far magnetically unmapped region was filled providing reliable ages of the oceanic crust, and suggesting that the Challenger Fracture Zone abruptly terminates west of the area of investigation. The survey in area C yielded valuable information on the trench morphology. The so far unique MCS profile south of Chiloé island shows a very wide trench and allows to extrapolate the general conditions encountered an area A southward to approximately 44° S. It can be stated that the situation is in sharp contrast to the basin structures detected by industry profiles further north in the Golfo de Corcovado.

Citation proposal
. Processed seismic data of Cruise SO161 SPOC 2001. https://gdk.gdi-de.org/geonetwork/srv/api/records/e4629f53-dc3b-4f7f-962f-ff16d5adcacd

INSPIRE
SDS

INSPIRE

Identification

File identifier: e4629f53-dc3b-4f7f-962f-ff16d5adcacd XML

Hierarchy level: Dataset

Online resource

Resource identifier

code: a734d0d2-be18-aadb-01a0-a0c7f8506fcd

Metadata language: English

Spatial representation type: Vector

Encoding

Format: Shapefile

Version: n/a

Projection

Classification of data and services

Topic category

Geoscientific information

Classification of data and services

Coupled resource

Classification of data and services

Coupled resource

Keywords

GEMET - INSPIRE themes, version 1.0 ( Theme )

Geologie
geology

GEMET - Concepts, version 2.4 ( Theme )

geophysics
Geophysik
raw material
Rohstoff

Other keywords

Keywords ( Theme )

Marine geology
Meeresgeologie
Seismics
Seismik
Two-dimensional seismic reflection
zweidimensionale Reflektionsseismik

Keywords ( Place )

Southeast Pacific Ocean
Südost-Pazifik
Chile

Geographic coverage

Temporal reference

Temporal extent

Date ( Creation ): 2001-11-29

Quality and validity

Lineage: During the period from 16th October 2001 to 29th November 2001 BGR acquired seismic lines off the Atlantic coast of South America. Lines SO161-018 and SO161-046G consist of raw data. Lines SO161-007, SO161-022, SO161-038, SO161-040 and SO161-046 consist of stacked data. Lines SO161-008, SO161-009, SO161-012, SO161-013, SO161-014, SO161-015, SO161-016, SO161-017, SO161-019, SO161-023, SO161-024, SO161-025, SO161-026, SO161-027, SO161-028, SO161-029, SO161-030, SO161-031, SO161-032, SO161-033, SO161-034, SO161-035, SO161-036, SO161-037, SO161-042, SO161-043, SO161-044, SO161-045, SO161-047 are migrated data.

Conformity

Explanation: siehe dazu die angegebene Durchführungsbestimmung

Restrictions on access and use

Access constraints: Allgemeine Geschäftsbedingungen, siehe http://www.bgr.bund.de/AGB - General terms and conditions, see http://www.bgr.bund.de/AGB_en. Die bereitgestellten Informationen sind bei Weiterverwendung wie folgt zu zitieren: Datenquelle: SO161 SPOC 2001, (c) BGR, Hannover, 2018