Geoscience Reference
In-Depth Information
Tracks of Hurricane Katrina and Hurricane Sandy
An excellent example of the need for monitoring can be seen
in videos showing the tracks of Hurricane Katrina in 2005 and
Hurricane Sandy In 2012. To see these tracks, view the ani-
mation
Tracks of Hurricane Katrina and Hurricane Sandy
.
The first part of this module is an animated cartoon illustrating
Hurricane Katrina's path. Subsequently, two videos follow the
path of this catastrophic hurricane as it moved across the Gulf
of Mexico. Watch for several things. First, look for the over-
all rotation of the system and how its path changed over time.
Also note the rapid intensification of the system as it migrated
across the Gulf. This intensification is obvious because the eye
of the storm suddenly becomes very prominent. At this point,
the storm was at its most powerful, specifically a Category 5
hurricane. Next, observe how the size of the eye fluctuated as
it approached the coast; this occurred because the storm's
strength varied somewhat before it made landfall. After you
watch the Katrina animation, turn your attention to the track
of Hurricane Sandy. Watch how this storm moved on a north-
erly track through the Caribbean and then followed the south-
eastern coast of the United States. Notice the approach of the
midlatitude jet stream as the storm moved farther north and
the pronounced westward turn the storm made prior to landfall
as the storm was incorporated into a strong extratropical low-
pressure system. As you watch these videos, think about why
satellite images such as these are essential for good monitoring
and how they save lives. Once you finish the video, be sure to
answer the questions at the end of the module to test your un-
derstanding of this concept.
warm 32°C (90°F). Katrina thus rapidly intensified to Category
5 status with sustained winds of 280 km/h (175 mph). At this
time, the storm had an extremely well-defined eye, as you can
see in Figure 8.26a. The storm subsequently weakened slightly
to a strong Category 3 shortly before it struck the Louisiana
coast on a Monday morning. The coastline was devastated as
far east as Florida, with thousands of homes and businesses lit-
erally flattened (Figure 8.26b) from the combined power of the
strong winds and a storm surge that spread up to 24 km (15 mi)
inland. The storm surge was highest in this region, up to 9 m
(30 ft) in some places, because it was in the right front quadrant
of the storm as it approached.
Although much of the Gulf Coast was blasted by the
storm, the most tragic consequences were experienced in New
Orleans. Established by the French in 1718 as a port on the
lower Mississippi River, this famous American city is actually
quite poorly located because it lies below sea level and therefore
floods very easily. This problem has been unevenly managed
since the town's birth by a continuously evolving complex of ca-
nals, pumping stations, and levees (high walls) along the Missis-
sippi River (to the south) and Lake Pontchartrain (to the north).
Given the poor geography of the area, experts in many fields had
long known that New Orleans was a disaster waiting to happen.
Disaster struck when Hurricane Katrina created a storm surge in
Lake Pontchartrain that caused several levees to fail, resulting in
severe flooding (Figure 8.26c) and the displacement of tens of
thousands of people. Of the 1800 people who died in the storm
along the Gulf, over 1400 fatalities occurred in New Orleans
alone. The economic cost of the storm was about $100 billion,
easily making it the most damaging storm in U.S. history.
In the aftermath of the storm, an intense national contro-
versy erupted over who was to blame for the catastrophe in
New Orleans. Fingers pointed everywhere. Some believed that
the residents of the city who remained as the storm approached
were at fault, even though about 100,000 people were poor
and did not have personal vehicles to evacuate. Others blamed
politicians from the mayor (a Democrat) to the president (a
Republican) for perceived inadequate planning and reactions.
Still others felt that the primary responsibility lay with the
slow response of the Federal Emergency Management
Agency
(FEMA), which was established in the late 1970s to provide
disaster relief in such an event. Regardless, the city was a mess
for months afterward, and some of it remains uninhabited to
this day. Although much of New Orleans has been rebuilt, a
thick scar remains from Hurricane Katrina and nervous eyes
turn to the Gulf every time a storm approaches.
Following Hurricane Katrina, the next disastrous storm to
strike the United States was Hurricane Sandy in late October
2012. Sandy was an unusual storm for several reasons related
to its path, time of year, size, landfall location, and interaction
with the midlatitude storm track. The storm originated in the
southeastern Caribbean as an easterly wave and proceeded on a
northerly track across Jamaica and eastern Cuba (Figure 8.27a)
as a Category 1 storm. After weakening slightly to a tropical
storm, it hit the Bahamas again as a Category 1 hurricane. Once
Sandy emerged into the Atlantic, it shadowed the eastern sea-
board, causing extensive coastal damage in the southeastern
United States, while remaining a Category 1 storm. Sandy then
combined with a strong midlatitude surface low over the eastern
United States to form a superstorm that extended over 1000 km
(600 mi) in width (Figure 8.27b). Given the size of the storm
and the broad wind field associated with it, Sandy is thought to
have contained the highest kinetic energy of any Atlantic storm
ever
recorded.
