590
Perhaps one of the most important research advances since DWH has been the
obvious recognition that large, deepwater oil spills exist in four dimensions (horizontal, vertical, temporal; Paris et al. 2020). During the DWH spill, a variety of
surface transport models were run, with varying degrees of success and sophistication, in an ad hoc ensemble (“mash up”) of model predictions, much like hurricane
“spaghetti” plots. While these transport models were appropriate for projecting surface expression of the spill necessary to inform oil spill response, very few operational 4-D models were available at the time (Liu et al. 2013). Since the DWH and
continuing today, there have been considerable model-related efforts to (1) better
describe in quantitative terms the “near-field” of deep marine blowouts at and above
the broken wellhead (Chap. 2), (2) connect the results of near-field models with the
far-field (i.e., 1000s of km
2
; Chap. 9) in four dimensions to predict oil and gas fate
and coincidence with biota, and (3) link near-far-field hydrodynamic and oil biodegradation models with spatially explicit ecosystem models to predict short- and longterm ecosystem outcomes (e.g., Peterson et al. 2003; Chaps. 31 and 32; Berenshtein
et al. 2020). In the event of the next deepwater blowout, there will be significantly
more capability to predict the fate and effects of oil in deep plumes, surfacing and
sequestered on the bottom. As described in the schematic depicted in Chap. 1 (there
Fig. 1.1), there are now linked quantitative models that describe what was only
envisioned qualitatively in the early days DWH spill. What is not obvious is if there
will be sufficient oceanographic observational data (current flow, temperature,
salinity) with which to populate these models as the next crisis unfolds.
34.4 What Else We Need to Know…
In much the same way former US Secretary of Defense Donald Rumsfeld described
known and unknown “unknowns,” our knowledge of the deep ocean realm and how
deep-sea blowouts may affect it has evolved from far too many “unknownunknowns” to now mostly “known-unknowns.” For a deep blowout of the magnitude of DWH, at that location, with that specific oil type, gas/oil ratio, etc., we are
now able to provide more complete information with which to inform response
efforts. This also includes the advisability of non-dispersant-related mitigation measures such as freshwater releases from impounded rivers and building of sand berms
to contain drifting oil offshore. Nevertheless, there remain a number of critical
“known-unknowns” that limit our present ability to confidently predict response,
fate, and effects of particular accidents and mitigation measures used to fight the
spill. Additional research targeted to close these remaining gaps is prioritized in
Murawski (2020). Importantly, as the state of knowledge of environmental conditions has progressed and trends in the oil and gas industries have evolved, so too
have our research priorities (e.g., Boesch et al. 1987).
While predicting impacts of a blowout analogous to DWH is difficult and idiosyncratic, there nevertheless is now an expanding body of empirical information and
S. A. Murawski et al.
Perhaps one of the most important research advances since DWH has been the
obvious recognition that large, deepwater oil spills exist in four dimensions (horizontal, vertical, temporal; Paris et al. 2020). During the DWH spill, a variety of
surface transport models were run, with varying degrees of success and sophistication, in an ad hoc ensemble (“mash up”) of model predictions, much like hurricane
“spaghetti” plots. While these transport models were appropriate for projecting surface expression of the spill necessary to inform oil spill response, very few operational 4-D models were available at the time (Liu et al. 2013). Since the DWH and
continuing today, there have been considerable model-related efforts to (1) better
describe in quantitative terms the “near-field” of deep marine blowouts at and above
the broken wellhead (Chap. 2), (2) connect the results of near-field models with the
far-field (i.e., 1000s of km
2
; Chap. 9) in four dimensions to predict oil and gas fate
and coincidence with biota, and (3) link near-far-field hydrodynamic and oil biodegradation models with spatially explicit ecosystem models to predict short- and longterm ecosystem outcomes (e.g., Peterson et al. 2003; Chaps. 31 and 32; Berenshtein
et al. 2020). In the event of the next deepwater blowout, there will be significantly
more capability to predict the fate and effects of oil in deep plumes, surfacing and
sequestered on the bottom. As described in the schematic depicted in Chap. 1 (there
Fig. 1.1), there are now linked quantitative models that describe what was only
envisioned qualitatively in the early days DWH spill. What is not obvious is if there
will be sufficient oceanographic observational data (current flow, temperature,
salinity) with which to populate these models as the next crisis unfolds.
34.4 What Else We Need to Know…
In much the same way former US Secretary of Defense Donald Rumsfeld described
known and unknown “unknowns,” our knowledge of the deep ocean realm and how
deep-sea blowouts may affect it has evolved from far too many “unknownunknowns” to now mostly “known-unknowns.” For a deep blowout of the magnitude of DWH, at that location, with that specific oil type, gas/oil ratio, etc., we are
now able to provide more complete information with which to inform response
efforts. This also includes the advisability of non-dispersant-related mitigation measures such as freshwater releases from impounded rivers and building of sand berms
to contain drifting oil offshore. Nevertheless, there remain a number of critical
“known-unknowns” that limit our present ability to confidently predict response,
fate, and effects of particular accidents and mitigation measures used to fight the
spill. Additional research targeted to close these remaining gaps is prioritized in
Murawski (2020). Importantly, as the state of knowledge of environmental conditions has progressed and trends in the oil and gas industries have evolved, so too
have our research priorities (e.g., Boesch et al. 1987).
While predicting impacts of a blowout analogous to DWH is difficult and idiosyncratic, there nevertheless is now an expanding body of empirical information and
S. A. Murawski et al.