The Mission de Nombre Dios had been founded in 1565 by Pedro Menendez, the first time someone had reached the new world. The mission was also the first religious mission in America to be erected, Menendez put Father Lopez in charge of the mission making him the first priest to practice in America. This mission sparked an eruption of development in colonial St. Augustine, the mission stands for more than the Christian faith but the culture that is still around today. The Great Cross on the church’s ground although built 400 years later has more history than its age tells.
The 70 ton, 208 feet tall cross tells a story unheard by most, when Pedro Menendez landed on the new world he had placed a small wooden cross in the soil, symbolizing the new culture that will develop in the new world.
The Great Cross is located behind the mission facing Hospital Creek a water passage connected to the Matanzas river and Saint Augustine inlet.
The mission and The Great Cross are visited by thousands of people each year and are a main attraction to some local trolleys. The rich culture of Saint Augustine is only enhanced by this religious structure, and although religious it can be appreciated by all due to its cultural importance in history. The mission has been destroyed multiple times by large hurricanes and attackers, however it was always rebuilt.
The Church and The Great Cross are currently in constant danger to nature and natural disasters, however with time this danger will only become more prevalent and more likely to strike.
In order to prevent the need to rebuild the structure another time, the necessity for protection and prevention is becoming essential.
Human interaction and pollution is causing the climate to change rapidly, the belief that humans can fix the damage they have caused is slowly fading away. Now it is time for mitigation and adaptation to the predicted effects of our changing earth that humans have stimulated. According to an article written by nation geographic sea levels have risen .13 inches in the past 20 years, which is twice as fast as the normal rise of the ocean for the past meters -41 80 years. As seen in the graph derived from the DNREC of Delaware there has been 1 foot of sea rise in the past 100 years and it is now predicted to rise twice as fast, allowing scientists to predict the rise to be around 1-4 feet by 2100.
Across the globe natural disasters and environmental change that have been a result from these changes have been a plague to communities we once thought were safe and protected. According to the C2ES (Center for climate and energy solutions) rising sea levels will not increase hurricane frequency however it will increase the intensity of the storms. This is seen in the recent encounter New jersey had with hurricane sandy, the areas waters reached its highest levels in history the same time hurricane sandy had hit causing massive costal flooding throughout the state. To examine the threat that these new changes could have on Saint Augustine and the Great cross, first the area that surrounds it must be evaluated.
The cross is on the coast of St. Augustine Florida and with rising seas, climate change and severe storms the cross could be wiped out. According to MissionandShrine.org the website for the church and The Great Cross, The Great Cross is 70 tons and fitted with 200 stainless steel panels. The more elevated portion of the cross contains 1.6 ft. x 10 ft. panels that are 3/16 in. thick, while the lower portion contain 4 ft. x 10 ft. and 5/16 in. thick panels. The Church did put in measures in order to prevent some damage to the cross, the bottom half of the cross is filled with concrete to increase stability against high winds. This however leaves the top portion to be very vulnerable to winds that can reach to 110+ MPH which are common with intense hurricanes.
Hurricanes although very dangerous to The Great cross are not the only threat to the cross, heavy rain storms could even effect the structure. Saint Augustine is at sea-level meaning that when rain fall occurs increased flooding also occurs. With rising sea levels this problem would only escalate, according to Center for Climate and Energy Solutions rainfall in storms would increase in quantity around 20 percent, this would lead to erosion. Increased erosion along United States coast line due to sediment loss has been very common and poses a big threat to the stability of The Great Cross. The process of coastal erosion is caused by Storms and flooding; these two factors are becoming more prevalent as sea levels continue to rise.
Although the cross is located on Hospital Creek and does not encounter large waves, storms are still a big factor to the process of coastal erosion. Storms cause the waters to have abnormal currents and can increase the speed of the same currents, causing the sediment on the shoreline to be taken and broken apart. Included in these storms are large quantities of rainfall, this causes flooding in low lying areas like Saint Augustine, the flooding when connected with the water in hospital creek if high enough could cause a small landslide.
However even without the effect of a large storms, flooding caused by small rain storms takes pieces of sediment and the sediment drains with it into the ocean or another source. This process is already occurring to shore lines across the globe, according to The Department of natural resources and Environmental Control of Delaware FEMA is creating a 100-year Floodplain in Delaware to combat costal erosion and save property from sea level rise.
Coastal cities and towns throughout America have been experiencing the same hardships that Florida has, the encroaching shore lines have made a need for these places to start taking preventative measures. Some of these measures are standing dunes, sea walls, jetties and beach dredging. These precautions in many places have become completely necessary and have helped save residential and commercial property throughout The United States. However, with the conditions that The Great Cross is encountering it would need several preventative measures in order to protect it.
The Great cross is very close to the shore and the erosion of the soil it stands on is very possible, in order to prevent the cross from collapsing measures must be taken in order to prevent the soil from eroding. The mission did take some measures in order to prevent the soil from eroding, although effective to current conditions it is possible that they may not be effective with the rapidly rising seas. The mission installed concrete revetments on the coasts of its land, revetments are non-corrodible materials placed on a bank of a shore line in order to prevent currents and small waves to have an impact on the land (USACE). However, with the impending sea level rise the revetments would no longer be effective, according to the C2ES the average global sea level rise for the next century will be approximately 4 feet.
The picture above shows that a raise in sea level in scale with what has been predicted will leave the revetments underwater and make them virtually useless. A measure that could be taken in place of the revetments is the use of bulk heads, bulk heads are erosion resistant materials like concrete or granite that are built into a wall to prevent soil from sliding seaward. The Bulkhead that would be most effective for the area around the cross would be Anchored/ tie-backed Bulkheads.
Most Bulkheads require a very stable ground structure to be built into however with the Anchor bulkheads they do not and have the same effectiveness. However, with the combination of sea level rise and large storms off the coast, the power of rough water could destroy the bulkheads. In order to prevent this problem, the use of break waters similar to the picture below derived from The US Army Corps of Engineers could be used as preventive action to reduce the impact that the bulkheads take.
Break waters are erosion resistant materials like granite or concrete built in a wall like matter off the coast of the protected area. These will take away the power of the water hitting the coast and reduce the likely hood that the coast will be eroded. The Great Cross location actually does allow it to have a natural break water, there is a small island in front of the cross’s coast that could be taking away some of the power from the water coming from the saint Augustine inlet.
However, this is not proven and requires field work and research, so as a precaution man made headland break waters closer to The Cross’s land must be created. Places that proved that this method is effective are coastal communities, coastal communities on bays or inlets use Bulkheads to protect them from heavy swells, mainly from storms. Notable towns like Santa Monica, California and Tokyo, japan rely not only on these Bulkheads but use break waters as well (USACE).
Although the break water would be much smaller in comparison to what is protecting the entire city of Tokyo, it has shown that it is very effective and should be considered. However, if sea level rise is to powerful and continues on the track that scientists believe it is going, the need for relocation would be a must. However, relocation is expensive and the location of the structure is a key factor for its importance, relocation should be the last resort of action on this land mark.