The Eruption of Toba

The Eruption of Toba

In Sumatra, Indonesia, approximately 74,000 years ago the volcano known as Toba erupted. This is thought to be the largest volcanic eruption in the last 2 million years. Because rocks are resilient, we can look at geological evidence to see that the eruption was colossal and affected a wide area. The aerosols from the eruption may have changed climate around the world. However, it is difficult to find (preserved) evidence of the impact of the eruption on the environment and the creatures that lived there. Scientists have speculated that the Toba event resulted in a sharp decline in human population and affected the pathway of human evolution. This sounds like an excellent event to teach us about the wide-spread and varied consequences of a catastrophic volcanic eruption. In fact, this event led to the Toba catastrophe theory.

The following site can give you one perspective of this famous event:
https://en.wikipedia.org/wiki/Toba_catastrophe_theory

Despite the potential for the eruption of Toba to be a regional (or even global) catastrophe, there are many scientists that claim the impacts of the eruption have been exaggerated and this eruption did not change the course of human history. Part of the controversy is centered on dating the event and part of the problem is varying interpretations of the scarce physical evidence of vegetation change, fossils and climate change. Our knowledge of the sequence of events and the severity of the consequences are pieced together from ancient evidence and hence interpretations are debated.

Your final assignment (part 2 of 2) is to write a scientific report about the debate surrounding the severity of the environmental and human impacts of the Toba eruption. Because of the controversy surrounding this event you will need to be diligent in your research and convincing in your writing.

The Scientific Report

Below is an outline of what I expect you to cover in your report. As always, use your own words, and follow instructions closely.

Introduction

You submitted a draft of the Introduction for Assignment #1. The instructions here are the same. Use the feedback you received from the last assignment to improve your Introduction for the major assignment.
Begin by just stating very simple facts all the details will come in later in the report.
Note the (approximate) date and location (a map is essential) of the events
Youll want to provide some introductory facts that will convince the reader that the event was a catastrophe. Your reader will wonder why you are writing about Toba so its best to explain briefly in the introduction why the event was significant.
Youll need to include a definition of super-eruption and bottleneck.
Draw comparisons to other volcanic eruptions (e.g. Krakatau) that were also considered devastating. How does Toba rank among the worlds most devastating eruptions? What other factors make it significant or unique (again you are trying to convince the reader why Toba deserves to be the topic of this assignment).
Briefly introduce the reader to the debate regarding the timing and consequences.
Statement of Aim (this may be a subsidiary heading under Introduction or simply a separate paragraph): just a sentence or two about what the report will cover.

Geological Setting of Toba

Describe in detail the geological setting; why is there a volcano at this site?
Provide the history of the volcano (past and subsequent eruptions and damage).
How active is this volcano?
Why are eruptions at this location explosive? What kind of volcano is this?
This section should be brief

The Toba super-eruption

This is the story of the main event of the eruption of Toba. This section will describe the physical processes that caused the devastation. Give the history of the event including more detail than you stated in the Introduction.
Be sure to say something of the source of material: do they know the composition? What were the types/volumes of material ejected? etc.
After you have covered the big eruption, consider what significant developments have happened since then; include some statement as to potential future eruptions of Toba.

The consequences of the catastrophe and the debate

From your readings, you will know that there are many dire consequences that could have resulted from the Toba events (for example: loss of life, loss of vegetation, climate change, population bottleneck).
In this section you should discuss the impacts of the eruption on the region (and possibly globally). What is a volcanic winter? Be sure to talk about the evidence that we use to determine these impacts.
When discussing this impact include information from both sides of the debate about the severity of the eruption, the timing of the event and the severity of the consequences.
Your goal should be to present both the evidence for and against the catastrophic nature of the Toba event.
Use this evidence to convince the reader

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