the competencies of the administration during the region's transition to constitutional autonomy. Geography Physical geography The municipality of Ponta Delgada is one of the larger administrative divisions in the archipelago, extending from the center of the island to the western coast. Ponta Delgada is bordered on the northeast by the municipality of Ribeira Grande, and southeast by relatively new municipality of Lagoa. Geomorphologically, Ponta Delgada covers a volcanic area composed of two structures: the Picos Region and Sete Cidades Massif. The Picos Region extends from the shadow of the ancient volcano of the Água de Pau Massif (known locally for the lake that rests within its volcanic crater: Lagoa do Fogo) until the area around the Sete Cidades caldera. It is a volcanic axial zone oriented generally in a northwest–southeast direction, essentially defined by several spatter cones and lava flows and predominantly covered by dense vegetation and pasture lands. Its relief is relatively planar, especially along the northern and southern coasts, where many of the urban communities are located. The Sete Cidades Massif, the other geomorphological structure that makes up the municipality of Ponta Delgada, consists of a central volcanic caldera and lake-filled cones which surround the crater. It occupies the extreme western part of the island, oriented along a similar northwest–southwest orientation, with many regional radial fractures marked by lava domes and spatter cones. The Sete Cidades Volcano at the center of the Massif consists of a caldera and a polygenetic volcanic field within it, that includes four lakes (two of which Lagoa Azul, the Blue Lake, and Lagoa Verde, the Green Lake, are linked). The caldera is almost circular and has evolved over the course of three phases. The first occurred 36,000 years ago forming the collapsed principal structure. The second phase conforms to a period approximately 29,000 years ago, when volcanic eruptions collapsed the northwest part of the structure. Finally, the third phase (about 16,000 years ago) caused the collapse of the north and northeastern portions of the caldera. Geologically, within the last 5,000 years, the central cone has been active (17 eruptions) and responsible for causing most of the activity in the archipelago, during that period. These geological eruptions were essentially trachyte eruptions of the sub-Plinian or Plinian type, with hydro-magmatic characteristics. The last eruption, at about 500 years ago, gave rise to the Caldeira Seca cone. Although there has been no historical activity today, its