When are Quarterly Estimated Taxes Due? Estimated taxes are due quarterly on specific dates during the year. The IRS mandates that the normal due dates for estimated taxes are April 15 for the first quarter of a year, June 15 for the second quarter, Sept. 15 for the third quarter and Jan.15 of the following year for the fourth quarter.
Salt water intrusion occurs in coastal freshwater aquifers when the different densities of both the saltwater and freshwater allow the ocean water to intrude into the freshwater aquifer.hen this occurs, it will move the saltwater freshwater interface inland, resulting in a higher saline concentration in the aquifers' water, rendering it useless for human consumption, unless it is treated. Figure 4. Saltwater Intrusion Situation(University of Florida, 2000)).
Divergent boundaries that develop in the ocean lead to the creation of mountains and volcanoes, according to the National Geographic. This occurs because magma from deep within the Earth rises at the point of a divergent boundary and creates new crust. When a divergent boundary occurs on land, it leads to the formation of a valley known as a rift. One example of a divergent boundary that is occurring on land is the Great Rift Valley. This divergent boundary is pulling the continent of Africa in two different directions. Eventually, this particular boundary is going to cause the continent to break apart into two separate land masses.