186
Our results indicate that for the DB_control scenario, highest oil residue deposits
are found at depths around the deep plume, especially north, northeast, and east of
the DWH site, including the DeSoto Canyon. Modeled oil residue is consistently
deposited around the GoM shoreline from western shore, along Florida Peninsula
and Florida Keys, and some deeper GoM interior regions along the bathymetric
slopes. Note the distant regions with elevated oil residue deposits along the shoreline near 94–95
°
W and the south to southeastern Florida coast.
The DB_noSubSfcLanding scenario shows a picture similar to that of DB_control, except deeper regions, and highlights the coastal areas with oil residue deposits. In general, sedimented oil residue in DB_tempBiodegrad case illustrates
surprising similarity with the control case in the coastal areas and some reduction in
deposits only around the DWH site and in the GoM interior along the bathymetric
slopes. Ocean circulation changes that dictate the outcome in DB_FALL case particularly limit the oil deposits along eastern GoM shore and Florida Keys (no deposits along the western Florida coast), no deposits in the north-northwest corner of the
GoM shoreline or south-southwest of the DWH site. Note the sediment formation
along the northern Cuba, easily explained by southward shift in the Florida Straights
position compared to the conditions in DB_control case (Fig. 11.2). More oil is
transported westward to the GoM interior with the eddies from the Loop Current,
which limits the oil available for deposition around the DWH blowout site.
Minor differences were found between the DB_VDROPJ_untreated and DB_
VDROPJ_treated scenarios, in which the DB_VDROPJ_treated case produces only
some spatial variability and some increase in spatial coverage of the areas with oil
residue deposits around the DWH site. In comparison to the DB_control case, both
of these scenarios show highest oil residue deposition in the coastal regions and
notably reduced deposition around the blowout site and DeSoto Canyon to the
northeast of that location.
Modeled sediments could be further validated against the observational studies
discussed in Sect. 11.2.3. The base-scale analysis of oil residues in surface sediments corrected for background values (Fig. 11.6; adapted from Fig. 11.4 in Romero
et al. 2017) indicated contamination was observed up to a distance of 180 km from
the DWH rig in the deep-sea area (depths >200 m) and up to 517 km in coastal
(including inshore habitats) and continental shelf areas. The spatial distribution of
oil residues show impacted regions in coastal areas of Louisiana (e.g., Barataria
Bay, Chandeleur Islands), Mississippi (e.g., Horn and Petit Bois Islands), Alabama
(e.g., Cat Island), and Florida (e.g., Panhandle area), and for offshore deep-sea areas
in the Mississippi Canyon, up- and downslope of the DWH well, and, to a lesser
extent, the DeSoto Canyon. In the deep sea, oil residue deposition was greater at
1300–1600 m depth up to 30 km from the DWH rig and at 1000–1300 m depth from
30 km to 175 km from the DWH rig (Fig. 11.6) following the trajectory of the seafloor and submerged plumes, respectively.
Schwing et al. 2017 found that relative to pre-DWH conditions, an increase in
210
Pb xs flux occurred in two distinct deep-sea areas of the northern GoM: (1) on an
east-northeast to west-southwest axis, stretching 230 km southwest and 140 km
northeast of the DWH wellhead, and (2) on a 70 km northeast to southwest axis near
the DeSoto Canyon (Fig. 11.7).
N. Perlin et al.
Our results indicate that for the DB_control scenario, highest oil residue deposits
are found at depths around the deep plume, especially north, northeast, and east of
the DWH site, including the DeSoto Canyon. Modeled oil residue is consistently
deposited around the GoM shoreline from western shore, along Florida Peninsula
and Florida Keys, and some deeper GoM interior regions along the bathymetric
slopes. Note the distant regions with elevated oil residue deposits along the shoreline near 94–95
°
W and the south to southeastern Florida coast.
The DB_noSubSfcLanding scenario shows a picture similar to that of DB_control, except deeper regions, and highlights the coastal areas with oil residue deposits. In general, sedimented oil residue in DB_tempBiodegrad case illustrates
surprising similarity with the control case in the coastal areas and some reduction in
deposits only around the DWH site and in the GoM interior along the bathymetric
slopes. Ocean circulation changes that dictate the outcome in DB_FALL case particularly limit the oil deposits along eastern GoM shore and Florida Keys (no deposits along the western Florida coast), no deposits in the north-northwest corner of the
GoM shoreline or south-southwest of the DWH site. Note the sediment formation
along the northern Cuba, easily explained by southward shift in the Florida Straights
position compared to the conditions in DB_control case (Fig. 11.2). More oil is
transported westward to the GoM interior with the eddies from the Loop Current,
which limits the oil available for deposition around the DWH blowout site.
Minor differences were found between the DB_VDROPJ_untreated and DB_
VDROPJ_treated scenarios, in which the DB_VDROPJ_treated case produces only
some spatial variability and some increase in spatial coverage of the areas with oil
residue deposits around the DWH site. In comparison to the DB_control case, both
of these scenarios show highest oil residue deposition in the coastal regions and
notably reduced deposition around the blowout site and DeSoto Canyon to the
northeast of that location.
Modeled sediments could be further validated against the observational studies
discussed in Sect. 11.2.3. The base-scale analysis of oil residues in surface sediments corrected for background values (Fig. 11.6; adapted from Fig. 11.4 in Romero
et al. 2017) indicated contamination was observed up to a distance of 180 km from
the DWH rig in the deep-sea area (depths >200 m) and up to 517 km in coastal
(including inshore habitats) and continental shelf areas. The spatial distribution of
oil residues show impacted regions in coastal areas of Louisiana (e.g., Barataria
Bay, Chandeleur Islands), Mississippi (e.g., Horn and Petit Bois Islands), Alabama
(e.g., Cat Island), and Florida (e.g., Panhandle area), and for offshore deep-sea areas
in the Mississippi Canyon, up- and downslope of the DWH well, and, to a lesser
extent, the DeSoto Canyon. In the deep sea, oil residue deposition was greater at
1300–1600 m depth up to 30 km from the DWH rig and at 1000–1300 m depth from
30 km to 175 km from the DWH rig (Fig. 11.6) following the trajectory of the seafloor and submerged plumes, respectively.
Schwing et al. 2017 found that relative to pre-DWH conditions, an increase in
210
Pb xs flux occurred in two distinct deep-sea areas of the northern GoM: (1) on an
east-northeast to west-southwest axis, stretching 230 km southwest and 140 km
northeast of the DWH wellhead, and (2) on a 70 km northeast to southwest axis near
the DeSoto Canyon (Fig. 11.7).
N. Perlin et al.