Thyroid replacement hormones usually are well tolerated. Symptoms that occur during treatment are often due to toxic, elevated levels of thyroid hormones and resulting symptoms from hyperthyroidism.
Facts about the New Madrid Seismic Zone. The New Madrid Seismic Zone (NMSZ) is the most active seismic area in the United States east of the Rocky Mountains. The NMSZ is located in southeastern Missouri, northeastern Arkansas, western Tennessee, western Kentucky and southern Illinois.
But New Madrid has experienced some big quakes in its history. Researchers have geologic evidence of several major earthquakes of around magnitude 7 and 8 striking the area over the past 4,500 years. More recently, the region experienced a series of strong quakes in 1811 and 1812. The first occurred in Arkansas on December 16, 1811, and scientistsâ best estimate for its strength is that it was a magnitude-7.7 earthquake. Six hours later, the region shook again with a similar-sized aftershock.