Bed forms of the Mediterranean undercurrent observed with side-scan sonar

Ferromanganese nodules and micro-hardgrounds associated with the Cadiz Contourite Channel (NE Atlantic): Palaeoenvironmental records of fluid venting and bottom currents

“…The CCC corresponds with the southern branch, along which the lower core of the MOW circulates with a present-day velocity ranging from 20 to 80 cm/s in the study area (e.g. Kenyon and Belderson, 1973;García et al, 2009). The GDR forms a topographic high that constricts the MOW circulation pathways, dividing the current into minor branches (Nelson et al, 1993;Hernández-Molina et al, 2003).…”

“…The development and evolution of this part of the Gulf of Cadiz margin has been controlled since the Late Messinian by the exchange of water masses through the Strait of Gibraltar, also affected by c1imatic cycles and tectonic events (e.g. Kenyon and Belderson, 1973;Llave et al, 2006;Voelker et al, 2006;Medialdea et al, 2009;León et al, 2010). We present a complete characterisation of these deposits based on a broad dataset that has led us to propose a genetic and evolutionary model Iinked to the mud volcanism-diapirism and palaeoceanographic evolution of the CCC, thus increasing knowledge about the interpretation of environmental changes.…”

“…The MOW velocities in different sectors of the Gulf of Cadiz show a high dispersion of values: from 300 cm/s in the proximity of the Strait of Gibraltar to 20-80 cm/s in the CCC (e.g. Kenyon and Belderson, 1973;Ambar and Howe, 1979a;Mulder et al, 2003). These current velocity variations are c1early conditioned by the bottom topography and give rise to sedimentary features such as channels and contourite deposits that have been influenced in the Late Quaternary by c1imatic and sea level changes, oceanographic conditions and local tectonic events García et al, 2009).…”

“…Kenyon and Belderson, 1973;Faugeres et al, 1984;Llave et al, 2001;Hernández-Molina et al, 2003;. This CDS is composed of five morphosedimentary sectors: the proximal scour and sand ribbon sector; the overflow sedimentary lobe sector; the channel and ridge sector; and the contourite drift and submarine canyon sector Hernández-Molina et al (2003).…”

Past deep‐ocean circulation and the paleoclimate record‐Gulf of Cadiz

“…Following the MOW westward from the Strait of Gibraltar, gravel lags and giant erosional features (GF in Figure 2) are first observed, and then,sand patches (SP in Figure 2), and sedi ment waves (SW in Figure 2) with their sand content decreasing westward [Melieres, 1974;Kenyon and Belderson, 1973;Nelson et al, 1999].A part of the MOW is channeled by the major, northern, intermediate or southern channels (MC, NC, IC, and SC, respectively in Figure 2) or by secondary channels (SeC in Figure 2), such as the Gil Eanes channel (GE in Figure 2). …”