Cataclysm

There exists an event referred to only as the cataclysm. 150 years ago, the Spectator range experienced the largest eruption in known history, destroying the silouette of the mountains and resulting in the near extinction of all humanoid populations. The remains of the cataclysm, both physically and in cultural memory, pervade every step and breath taken by those who live in its wake.

Geology

The Spectator range is andesitic, but is very high in silica to the point of nearly crossing the threshold to be considered rhyolitic. Rhyolitic rock is viscous when magmatic, making it move slowly in chambers and volcanic conduits. This 'clogging' effect results in heavy buildup of pressure in active sites, resulting in explosive and destructive eruptions when they do occur. Eruptions are less common the more destructive they are, as more energy buildup over a very long period of time yields more energy released. The chamber that erupted in the cataclysm had not done so for hundreds of millions of years- the mountains that formed atop it were not 'volcanoes' in the sense that their cores were not active conduits, rather, the whole of the mountain(s) sat atop a massive magma chamber. The mountains that existed were the result of smaller-scale volcanic activity over millions of years- fed by the same chamber, but only as effusive eruptions; small releases of energy and material through proportionally tiny conduits and vents. As a result, when the chamber erupted it did not form a traditional 'volcano shape', ie: a mountain topped with a crater. Instead, the caldera the eruption created spanned the space where multiple mountains had previously rested, breaking up the shape of the range.

Chemistry

Because the range is the result of oceanic subduction, there is a significant amount of water that mixes with the rock that eventually makes its way to the surface. This, in tandem with elements in the rock itself that escape when melted, creates a mixture of gasses that contribute to the pressure in the magma chamber. Upon eruption, these gasses are expelled into the atmosphere and affect the surrounding area- many of them toxic. Because of the scale of the eruption, many of these materials found their way both across the continent and into the stratosphere- circulating with global wind patterns. Their intensity diminished with distance from the volcano, but their effects were still seen across a wide area.

Sulfur dioxide, and some hydrogen chloride, that made it to the stratosphere reacts with ozone, depleting ozone levels and resulting in sulfuric acid (or hydrochloric acid) formation in the stratosphere, which fell back to the surface in the subsequent months as acid rain, damaging crops and poisoning water sources. Further crop and ecological damage resulted from secondary contaminations such as soil nutrient destruction, aluminum leaching, pH decline, and nitrogen pollution. Merfolk experienced famines and sicknesses from the acidification of northern waters.

The depletion of ozone in the stratosphere led to UV stresses in high latitudes, the worst of it lasting up to a year and severely damaging humanoid, animal, and plant populations. Direct sunlight resulted in sunburn and eye damage after just 15 minutes exposed in the months after the eruption. Later on, DNA damage rates increased, further exacerbating population decline. The results of this remained evident in all those who survived the cataclysm- many who were lucky enough to grow old died from rare diseases and cancers.

Hydrogen sulfide was also expelled in large quantities, acutely affecting nearby populations varying with concentration and exposure time. Symptoms ranged from nausea, insomnia, and/or migraines, to respiratory damage, eye damage, altered breathing, fatigue, or death, depending on the extent of exposure. Sulfide sickness is the major contributor to the abandonment and death of northern communities- even those that survived the physical eruption suffered from swift chemical death. Long-term, chronic effects touched latitudes as low as 15 degrees, with wide scale eye damage, respiratory damage such as chronic bronchitis, and some neurological effects appearing in the population.

Because they are adapted to thrive in hydrothermal environments, in which sulfides are an essential part of the life cycle, nightlings have zinc bound to the hemocyanin in their blood that makes hydrogen sulfide intert- therefore, they did not experience the sicknesses that tellurans did. They suffered from the effects of other aerosols, but because sulfide sickness was the most widespread and severe, they seemed oddly immune to many of the aftereffects of the eruption.

Hydrogen fluoride was degassed, but in nowhere near the quantities of sulfides, dioxides, or water vapor. Still, because of its incredibly poisonous nature, its effects were seen on populations very close to the volcano. Anyone unlucky enough to be incredibly near the eruption would have died just a few days later as a result of hydrogen fluoride poisoning.

Other aerosols that were expelled, such as particulate matter or carbon dioxide, were carried on global winds to much of the continent. These materials caused less severe symptoms, such as breathing difficulties or heart problems. Unlike sulfide poisoning, though, these would diminish with time in all but the most drastic cases, whereas sulfide poisoning was chronic from exposure in all but the lightest cases.

Ecology

Lava and pyroclastic flow covered the flank of the volcano, destroying anything (plant, animal, or infrastructure) that was there and forcing that area of the mountains to go into primary succession. 150 years later, the majority of that mountain face is now grassland- the forest it once was has another few hundred years to regrow.

Droughts followed in the months after the eruption, resulting from the disruption of the water cycle by stratospheric aerosols attenuating sunlight. Precipitation reduced to around 3/4ths of normal levels. This placed stress on agriculture in the south, but in the north- combined with the stresses of acidification- it further served to devastate any hope of successful crop yields. Inland merfolk experiences drastic water level decreases, which in turn intensified the effects of acidification in lakes and rivers. Some well-established lake-living merfolk communities were completely destroyed by the cataclysm, and inland merfolk are rarer now.

Thick layers of ash covered a wide range of the mountains and surrounding lands- much of those areas that weren't already forests are now. This is not only a result of the sudden increase in soil richness being able to support forests where it previously hadn't, but because of the quick advance of the domesticated species of tree (mostly pines and redwood) that had been used for building satyrs' cities. After the destruction of said cities and their subsequent abandonment, whether by death or emigration, these species, selected over generations to grow fast and tall and moldeable, grew unchecked and outcompeted many other species, including those in areas that were not forests prior to the cataclysm. The northern forests in what remains of Yañaiveut, then, are now dominated by just two or three species of tree, choking out all others and drastically reducing biodiversity. They grow thick, preventing much of the understory from developing as it would in a healthy forest. Insects, birds, and other animals that relied on specific plant species for their habitat, food sources, or other needs suffered- their ranges changing to avoid these forests or populations dwindling to fractions of what they were.

Ipotanes' prairies experiences a shrinkage as these forests expanded. Much more of the Central Basin used to be grassland, but after the cataclysm, it was taken over by these almost artificial forests.

A significant portion of the ash cloud rose into the stratosphere and, once there, blocked sunlight- heavily for weeks, moderately for months, and this dampening effect continued to affect climate for years. The Three-Year Winter resulted, as global temperatures dropped by between 40-45℉, and did not fully recover for nearly a decade, though cool summers returned within 4-5 years.

Culture

The world in the wake of the cataclysm feels more fragile. Even 150 years later, the pervasive knowledge that something like this happened looms over the people as they go about their daily lives. They know they are missing history- from family lines that get unclear past that time, to the forgetting of ancient technologies and functions that were once ubiquitous. There is an incompleteness that lingers, too, by nature of what is missing. Every person alive knows there are gaps, but doesn't know what belongs there, and so must instead live with the emptiness. It touches differently by location and species and personal affect- some of these specifics can be found under the Species tab.