Resuspended bottom sediments off Florida
The distinct and vibrant colors seen in this image of South Florida are caused by sedimentation. Runoff from the land surface carries eroded materials into the Gulf of Mexico; this is exacerbated by the flooding associated with hurricanes and other major storm events. The water here is very shallow by ocean standards, only about 30 to 600 meters (100 â€“ 2000 feet), while the average depth of the oceans is about 3790 meters (or about 2.4 miles). Occasionally, deep ocean currents bring some of these sediments back towards the surface. The zone within the ocean closest to the land, or the continental shelf, is very active biologically. This is mainly because of its shallowness; sunlight is only able to penetrate to a depth of about 200 meters (650 feet) at best, while in some places it can only reach a meter or two (3-6 feet). However, it is this very shallowness that makes this ecosystem vulnerable to the influence of human activity. Coastal development, sea level rise, pollution from industrial and agricultural activities, and even the wakes from motor boats can have an adverse impact here.