scholarly journals Seismic Crustal Structure and Morphotectonic Features Associated With the Chain Fracture Zone and Their Role in the Evolution of the Equatorial Atlantic Region

2020 ◽  
Vol 125 (10) ◽  
Author(s):  
Milena Marjanović ◽  
Satish C. Singh ◽  
Emma P. M. Gregory ◽  
Ingo Grevemeyer ◽  
Kevin Growe ◽  
...  
Keyword(s):  
Crustal Structure ◽  
Fracture Zone ◽  
Equatorial Atlantic ◽  
Atlantic Region

Interannual sea surface chlorophyll-a signature in the tropical Atlantic

2021 ◽  
Author(s):  
Fanny Chenillat ◽  
Julien Jouanno ◽  
Serena Illig ◽  
Founi Mesmin Awo ◽  
Gaël Alory ◽  
...  
Keyword(s):  
Surface Temperature ◽  
Sea Surface ◽  
Tropical Atlantic ◽  
Cold Tongue ◽  
Equatorial Atlantic ◽  
Atlantic Region ◽  
The North ◽  
Sst Anomaly ◽  
Equatorial Band ◽  
North Tropical Atlantic

<div><span>Surface chlorophyll-<em>a </em>concentration (CHL-<em>a</em>) remotely observed by satellite shows a marked seasonal and interannual variability in the Tropical Atlantic, with potential consequences on the marine trophic web. Seasonal and interannual CHL-<em>a </em>variability peaks in boreal summer and shows maxima in the equatorial Atlantic region at 10˚W, spreading from 0 to 30˚W. In this study, we analyze how the remotely-sensed surface CHL-<em>a </em>responds to the leading climate modes affecting the interannual equatorial Atlantic variability over the 1998-2018 period, namely the Atlantic Zonal Mode (AZM) and the North Tropical Atlantic Mode (NTA, also known as the Atlantic Meridional Mode). The AZM is characterized by anomalous warming (or cooling) along the eastern equatorial band. In contrast, the NTA is characterized by an interhemispheric pattern of the sea surface temperature (SST), with anomalous warm (cold) conditions in the north tropical Atlantic region and weak negative (positive) SST anomalies south of the equator. We show that both modes significantly drive the interannual Tropical Atlantic surface CHL-<em>a </em>variability, with different timings and contrasted modulation on the eastern and western portions of the cold tongue area. Our results also reveal that the NTA slightly dominates (40%) the summer tropical Atlantic interannual variability over the last two decades, most probably because of a positive phase of the Atlantic multidecadal oscillation. For each mode of variability, we analyze an event characterized by an extreme negative sea surface temperature (SST) anomaly in the Atlantic equatorial band. Both modes are associated with a positive CHL-<em>a </em>anomaly at the equator. In 2002, a negative phase of the NTA led to cold SST anomaly and high positive CHL-<em>a </em>in the western portion of the cold tongue, peaking in June-July and lasting until the end of the year. In contrast, in 2005, a negative phase of the AZM drove cool temperature and positive CHL-<em>a </em>in the eastern equatorial band, with a peak in May-June and almost no signature after August. Such contrasted year to year conditions can affect the marine ecosystem by changing temporal and spatial trophic niches for pelagic predators, thus inducing significant variations for ecosystem functioning and fisheries.</span></div>

Lower Cretaceous to Eocene sedimentary transverse ridge at the Romanche Fracture Zone and the opening of the equatorial Atlantic

2001 ◽  
Vol 176 (1-4) ◽  
pp. 101-119 ◽  
Author(s):  
L Gasperini ◽  
D Bernoulli ◽  
E Bonatti ◽  
A.M Borsetti ◽  
M Ligi ◽  
...  
Keyword(s):  
Fracture Zone ◽  
Lower Cretaceous ◽  
Equatorial Atlantic ◽  
Transverse Ridge ◽  
Romanche Fracture Zone

scholarly journals Crustal structure of the French Guiana margin, West Equatorial Atlantic

2007 ◽  
Vol 169 (3) ◽  
pp. 964-987 ◽  
Author(s):  
C. J. Greenroyd ◽  
C. Peirce ◽  
M. Rodger ◽  
A. B. Watts ◽  
R. W. Hobbs
Keyword(s):  
Crustal Structure ◽  
French Guiana ◽  
Equatorial Atlantic

Transform migration and vertical tectonics at the Romanche fracture zone, equatorial Atlantic

1994 ◽  
Vol 99 (B11) ◽  
pp. 21779-21802 ◽  
Author(s):  
E. Bonatti ◽  
M. Ligi ◽  
L. Gasperini ◽  
A. Peyve ◽  
Y. Raznitsin ◽  
...  
Keyword(s):  
Fracture Zone ◽  
Equatorial Atlantic ◽  
Romanche Fracture Zone
Sign in / Sign up

Export Citation Format

Share Document